Mechanical influences on endothelial cell network formation in vitro

While both the restoration of the blood supply and an appropriate local mechanical environment are critical for uneventful bone healing, their influence on each other remains unclear. Human bone fracture haematomas (<72h post-trauma) were cultivated for 3 days in fibrin matrices, with or without cyclic compression. Conditioned medium from these cultures enhanced the formation of vessel-like networks by HMEC-1 cells, and mechanical loading further elevated it, without affecting the cells’ metabolic activity. While haematomas released the angiogenesis-regulators, VEGF and TGF-β1, their concentrations were not affected by mechanical loading. However, direct cyclic stretching of the HMEC-1 cells decreased network formation. The appearance of the networks and a trend towards elevated VEGF under strain suggested physical disruption rather than biochemical modulation as the responsible mechanism. Thus, early fracture haematomas and their mechanical loading increase the paracrine stimulation of endothelial organisation in vitro, but direct periodic strains may disrupt or impair vessel assembly in otherwise favourable conditions.

Temporal Characterization of Ossification of the Crania in Australian Subadults: New standards for Age Estimation using Computed Tomography

After attending this presentation, attendees will gain awareness of the ontogeny of cranial maturation, specifically: (1) the fusion timings of primary ossification centers in the basicranium; and (2) the temporal pattern of closure of the anterior fontanelle, to develop new population-specific age standards for medicolegal death investigation of Australian subadults. This presentation will impact the forensic science community by demonstrating the potential of a contemporary forensic subadult Computed Tomography (CT) database of cranial scans and population data, to recalibrate existing standards for age estimation and quantify growth and development of Australian children. This research welcomes a study design applicable to all countries faced with paucity in skeletal repositories. Accurate assessment of age-at-death of skeletal remains represents a key element in forensic anthropology methodology. In Australian casework, age standards derived from American reference samples are applied in light of scarcity in documented Australian skeletal collections. Currently practitioners rely on antiquated standards, such as the Scheuer and Black1 compilation for age estimation, despite implications of secular trends and population variation. Skeletal maturation standards are population specific and should not be extrapolated from one population to another, while secular changes in skeletal dimensions and accelerated maturation underscore the importance of establishing modern standards to estimate age in modern subadults. Despite CT imaging becoming the gold standard for skeletal analysis in Australia, practitioners caution the application of forensic age standards derived from macroscopic inspection to a CT medium, suggesting a need for revised methodologies. Multi-slice CT scans of subadult crania and cervical vertebrae 1 and 2 were acquired from 350 Australian individuals (males: n=193, females: n=157) aged birth to 12 years. The CT database, projected at 920 individuals upon completion (January 2014), comprises thin-slice DICOM data (resolution: 0.5/0.3mm) of patients scanned since 2010 at major Brisbane Childrens Hospitals. DICOM datasets were subject to manual segmentation, followed by the construction of multi-planar and volume rendering cranial models, for subsequent scoring. The union of primary ossification centers of the occipital bone were scored as open, partially closed or completely closed; while the fontanelles, and vertebrae were scored in accordance with two stages. Transition analysis was applied to elucidate age at transition between union states for each center, and robust age parameters established using Bayesian statistics. In comparison to reported literature, closure of the fontanelles and contiguous sutures in Australian infants occur earlier than reported, with the anterior fontanelle transitioning from open to closed at 16.7±1.1 months. The metopic suture is closed prior to 10 weeks post-partum and completely obliterated by 6 months of age, independent of sex. Utilizing reverse engineering capabilities, an alternate method for infant age estimation based on quantification of fontanelle area and non-linear regression with variance component modeling will be presented. Closure models indicate that the greatest rate of change in anterior fontanelle area occurs prior to 5 months of age. This study complements the work of Scheuer and Black1, providing more specific age intervals for union and temporal maturity of each primary ossification center of the occipital bone. For example, dominant fusion of the sutura intra-occipitalis posterior occurs before 9 months of age, followed by persistence of a hyaline cartilage tongue posterior to the foramen magnum until 2.5 years; with obliteration at 2.9±0.1 years. Recalibrated age parameters for the atlas and axis are presented, with the anterior arch of the atlas appearing at 2.9 months in females and 6.3 months in males; while dentoneural, dentocentral and neurocentral junctions of the axis transitioned from non-union to union at 2.1±0.1 years in females and 3.7±0.1 years in males. These results are an exemplar of significant sexual dimorphism in maturation (p<0.05), with girls exhibiting union earlier than boys, justifying the need for segregated sex standards for age estimation. Studies such as this are imperative for providing updated standards for Australian forensic and pediatric practice and provide an insight into skeletal development of this population. During this presentation, the utility of novel regression models for age estimation of infants will be discussed, with emphasis on three-dimensional modeling capabilities of complex structures such as fontanelles, for the development of new age estimation methods.

Sensorineural hearing loss after treatment for head and neck cancer : a review of the literature

Background Definitive cisplatin-based is increasingly delivered as the treatment of choice for patients with head and neck cancer. Sensorineural hearing loss is a significant long term side effect of cisplatin-based chemoradiation and is associated with potential major quality of life issues for patients. Purpose The purpose of this manuscript was to review the mechanism behind sensorineural hearing loss in patients treated with cisplatin-based chemoradiation, including incidence, the contributions of radiotherapy and cisplatin to sensorineural hearing loss and the impact of the toxicity on patient quality of life. Methods Database searches were conducted through PubMed (National Centre for Biotechnology Information) and OvidSP Medline via the Queensland University of Technology Library website. General article searches were conducted through the online search engine Google Scholar. Articles were excluded if the full-text was unavailable, they were not in English or if they were published prior to 1990. Keywords included hearing loss, ototoxicity, cancer, quality of life, cisplatin and radiotherapy. Results/Discussion The total number of journal articles accessed was 290. Due to exclusion criteria, 129 articles were deemed appropriated for review. Findings indicated that sensorineural hearing loss is a significant, long term complication for patients treated with cisplatin-based chemoradiation. Current literature recognises the ototoxic effects of cisplatin and cranial irradiation as separate entities, however the impact of combined modality therapy on sensorineural hearing loss is seldom reported. Multiple risk factors for hearing loss are described, however there are contradictory opinions on incidence and severity and the exact radiation dose threshold responsible for inducing hearing loss in patients receiving combined modality therapy. Sensorineural hearing loss creates a subset of complexities for patients with head and neck cancer and that these patients face significant quality of life impairment. Conclusion The literature review identified that sensorineural hearing loss is a major quality of life issue for patients treated with cisplatin-based chemoradiation for head and neck cancer. Further investigation evaluating the contribution of cisplatin-based chemoradiation to sensorineural hearing loss and the subsequent effect on patient quality of life is warranted.

Anatomical modelling of the pregnant radiotherapy patient

This study aimed to take existing anatomical models of pregnant women, currently used for radiation pro-tection and nuclear medicine dose calculations, and adapt them for use in the calculation of fetal dose from external beam radiotherapy (EBRT). The models investigated were ‘KATJA’, which was provided as an MCNPX geometry file, and ‘RPI-P6’, which was provided in a simple, voxelized bina-ry format. In-house code was developed, to convert both mod-els into an `egsphant’ format, suitable for use with DOSXYZnrc. The geometries and densities of the resulting phantoms were evaluated and found to accurately represent the source data. As an example of the use of the phantoms, the delivery of a cranial EBRT treatment was simulated using the BEAMnrc and DOSXYZnrc Monte Carlo codes and the likely out-of-field doses to the fetus in each model was calculated. The results of these calculations showed good agreement (with-in one standard deviation) between the doses calculated in KATJA and PRI-P6, despite substantial anatomical differ-ences between the two models. For a 36 Gy prescription dose to a 233.2 cm3 target in the right brain, the mean doses calcu-lated in a region of interest covering the entire uterus were 1.0 +/- 0.6 mSv for KATJA and 1.3 +/- 0.9 mSv for RPI-P6. This work is expected to lead to more comprehensive studies of EBRT treatment plan design and its effects on fetal dose in the future.

Groucho homologue Grg5 interacts with the transcription factor Runx2-Cbfa1 and modulates its activity during postnatal growth in mice

Runx2-Cbfal, a Runt transcription factor, plays important roles during skeletal development. It is required for differentiation and function of osteoblasts. In its absence, chondrocyte hypertrophy is severely impaired and there is no vascularization of cartilage templates during skeletal development. These tissue-specific functions of Runx2 are likely to be dependent on its interaction with other proteins. We have therefore searched for proteins that may modulate the activity of Runx2. The yeast two-hybrid system was used to identify a groucho homologue, Grg5, as a Runx2-interacting protein. Grg5 enhances Runx2 activity in a cell culture-based assay and by analyses of postnatal growth in mice we demonstrate that Grg5 and Runx2 interact genetically. We also show that Runx2 haploinsufficiency in the absence of Grg5 results in a more severe delay in ossification of cranial sutures and fontanels than occurs with Runx2 haploinsufficiency on a wild-type background. Finally, we find shortening of the proliferative and hypertrophic zones, and expansion of the resting zone in the growth plates of Runx2(+/-)Grg5(-/-) mice that are associated with reduced Ihh expression and Indian hedgehog (Ihh) signaling. We therefore conclude that Grg5 enhances Runx2 activity in vivo.

The Miocene of Western Asia; Fossil mammals at the crossroads of faunal provinces and climate regimes

Being at the crossroads of the Old World continents, Western Asia has a unique position through which the dispersal and migration of mammals and the interaction of faunal bioprovinces occurred. Despite its critical position, the record of Miocene mammals in Western Asia is sporadic and there are large spatial and temporal gaps between the known fossil localities. Although the development of the mammalian faunas in the Miocene of the Old World is well known and there is ample evidence for environmental shifts in this epoch, efforts toward quantification of habitat changes and development of chronofaunas based on faunal compositions were mostly neglected. Advancement of chronological, paleoclimatological, and paleogeographical reconstruction tools and techniques and increased numbers of new discoveries in recent decades have brought the need for updating and modification of our level of understanding. We under took fieldwork and systematic study of mammalian trace and body fossils from the northwestern parts of Iran along with analysis of large mammal data from the NOW database. The data analysis was used to study the provinciality, relative abundance, and distribution history of the closed- and open-adapted taxa and chronofaunas in the Miocene of the Old World and Western Asia. The provinciality analysis was carried out, using locality clustering, and the relative abundance of the closed- and open-adapted taxa was surveyed at the family level. The distribution history of the chronofaunas was studied, using faunal resemblance indices and new mapping techniques, together with humidity analysis based on mean ordinated hypsodonty. Paleoichnological studies revealed the abundance of mammalian footprints in several parts of the basins studied, which are normally not fossiliferous in terms of body fossils. The systematic study and biochronology of the newly discovered mammalian fossils in northwestern Iran indicates their close affinities with middle Turolian faunas. Large cranial remains of hipparionine horses, previously unknown in Iran and Western Asia, are among the material studied. The initiation of a new field project in the famous Maragheh locality also brings new opportunities to address questions regarding the chronology and paleoenvironment of this classical site. Provinciality analysis modified our previous level of understandings, indicating the interaction of four provinces in Western Asia. The development of these provinces was apparently due to the presence of high mountain ranges in the area, which affected the dispersal of mammals and also climatic patterns. Higher temperatures and possibly higher co2 levels in the Middle Miocene Climatic Optimum apparently favored the development of the closed forested environments that supported the dominance of the closed-adapted taxa. The increased seasonality and the progressive cooling and drying of the midlatitudes toward the Late Miocene maintained the dominance of open-adapted faunas. It appears that the late Middle Miocene was the time of transition from a more forested to a less forested world. The distribution history of the closed- and open-adapted chronofaunas shows the presence of cosmopolitan and endemic faunas in Western Asia. The closed-adapted faunas, such as the Arabian chronofauna of the late Early‒early Middle Miocene, demonstrated a rapid buildup and gradual decline. The open-adapted chronofaunas, such as the Late Miocene Maraghean fauna, climaxed gradually by filling the opening environments and moving in response to changes in humidity patterns. They abruptly declined due to demise of their favored environments. The Siwalikan chronofauna of the early Late Miocene remained endemic and restricted through all its history. This study highlights the importance of field investigations and indicates that new surveys in the vast areas of Western Asia, which are poorly sampled in terms of fossil mammal localities, can still be promising. Clustering of the localities supports the consistency of formerly known patterns and augments them. Although the quantitative approach to relative abundance history of the closed- and open-adapted mammals harks back to more than half a century ago, it is a novel technique providing robust results. Tracking the history of the chronofaunas in space and time by means of new computational and illustration methods is also a new practice that can be expanded to new areas and time spans.

Brain and Spinal Cavernomas : Helsinki Experience

Cavernomas are rare neurovascular lesions, encountered in up to 10% of patients harboring vascular abnormalities of the CNS. Cavernomas consist of dilated thin-walled sinusoids or caverns covered by a single layer of endothelium. Due to advancements in neuroradiology, the number of cavernoma patients coming to be evaluated in neurosurgical practice is increasing. In the present work, we summarized our results on the treatment of cavernomas. Particular attention was paid to uncommon locations or insufficiently investigated cavernomas, including 1. Intraventricular cavernomas; 2. Multiple cavernomas; 3. Spinal cavernomas; and 4. Temporal lobe cavernomas. After analyzing the patient series with these lesions, we concluded that: 1. IVCs are characterized by a high tendency to cause repetitive hemorrhages in a short period of time after the first event. In most patients, hemorrhages were not life-threatening. Surgery is indicated when re-bleedings are frequent and the mass-effect causes progressive neurological deterioration. Modern microsurgical techniques allow safe removal of the IVC, but surgery on fourth ventricle cavernomas carries increased risk of postoperative cranial nerve deficits. 2. In MC cases, when the cavernoma bleeds or generates drug-resistant epilepsy, microsurgical removal of the symptomatic lesion is beneficial to patients. In our series, surgical removal of the most active cavernoma usually the biggest lesion with signs of recent hemorrhage - was safe and prevented further bleedings. Epilepsy outcome showed the effectiveness of active treatment of MCs. However, due to the remaining cavernomas, epileptogenic activity can persist postoperatively, frequently necessitating long-term use of antiepileptic drugs. 3. Spinal cavernomas can cause severe neurological deterioration due to low tolerance of the spinal cord to mass-effect with progressive myelopathy. When aggravated by extralesional massive hemorrhage, neurological decline is usually acute and requires immediate treatment. Microsurgical removal of a cavernoma is effective and safe, improving neurological deficits. Sensorimotor deficits and pain improved postoperatively at a high rate, whereas bladder dysfunction remained essentially unchanged, causing social discomfort to patients. 4. Microsurgical removal of temporal lobe cavernomas is beneficial for patents suffering from drug-resistant epilepsy. In our series, 69% of patients with this condition became seizure-free postoperatively. Duration of epilepsy did not correlate with seizure prognosis. The most frequent disabling symptom at follow-up was memory disorder, considered to be the result of a complex interplay between chronic epilepsy and possible damage to the temporal lobe during surgery.

A taxonomic mystery for more than 180 years: the identity and systematic position of Brachysaura minor (HARDWICKE & GRAY, 1827)

Brachysaura is a monotypic genus of agamid lizard found in the Indian subcontinent; the identity and systematic position of B. minor has been long debated, and it has at times been subsumed into Agama, Charasia and Laudakia, with some authors suggesting affinities to Calotes. We constructed nuclear and mitochondrial phylogenetic trees including Brachysaura and allied agamid genera to resolve its phylogenetic position. We also compared osteology and external morphology with the genera Agama, Calotes and Laudakia. Hemipenial morphology was compared with Calotes and some other agamids from South Asia. Both nuclear and mitochondrial phylogenies demonstrate that Brachysaura is nested within the widespread South and Southeast Asian genus Calotes, with which it also shares certain external morphological, osteological and hemipenial characters. Adaptations to ground dwelling in Brachysaura minor has resulted in unique modifications to its body plan, which is likely why generic allocation has been long confused. This study also highlights the need for an integrated systematic approach to resolve taxonomic ambiguity in Asian agamids.

Avaliação da estabilidade da cirurgia de avanço mandibular através da superposição de modelos tridimensionais

Embora a cirurgia de avanço mandibular seja considerada um procedimento altamente estável, existem algumas preocupações clínicas em relação a mudanças nos côndilos e nos segmentos proximais, que podem levar a recidiva sagital e abertura de mordida. A avaliação dos resultados da cirurgia através de ferramentas de geração e superposição de modelos virtuais tridimensionais (3D) permite a identificação e quantificação dos deslocamentos e remodelação óssea que podem ajudar a explicar as interações entre os componentes dentários, esqueléticos e de tecido mole que estão relacionados a resposta ao tratamento. Este estudo observacional prospectivo avaliou, através de tomografia computadorizada de feixe cônico (CBCT), mudanças na posição/remodelação 3D dos ramos mandibulares, côndilos e mento. Assim, exames CBCT de 27 pacientes foram adquiridos antes da cirurgia (T1), imediatamente após a cirurgia(T2), e 1 ano após a cirurgia(T3). Uma técnica automática de superposição na base do crânio foi utilizada para permitir a avaliação das mudanças ocorridas nas regiões anatômicas de interesse (RAI). Os deslocamentos foram visualizados e quantificados em mapas coloridos 3D através da ferramenta de linha de contorno (ISOLINE). Pelo teste t pareado compararam-se as mudanças entre T1-T2 e T2-T3. O coeficiente de correlação de Pearson verificou se os deslocamentos ocorridos nas RAI foram correlacionados entre si e entre os tempos de avaliação. O nível de significância foi determinado em 0,05. O avanço mandibular médio foi de 6,813,2mm em T2 e 6,363,41mm em T3 (p=0,13). Entre T2 e T3, a posição do mento variou positivamente (≥2mm) em 5 pacientes negativamente em 7. 12% dos pacientes sofreram recidivas ≥4mm. Para todas as outras RAI avaliadas, apenas a porção inferior dos ramos (lado direito - 2,342,35mm e lado esquerdo 2,972,71mm) sofreram deslocamentos médios >2mm com a cirurgia. No acompanhamento em longo prazo, esse deslocamento lateral da porção inferior dos ramos foi mantido (lado direito - 2,102,15mm, p=0,26; e lado esquerdo -2,762,80, p=0,46), bem como todos os outros deslocamentos observados (p>0,05). As mudanças na posição do mento foram correlacionadas a adaptações pós-cirúrgicas nos bordos posteriores dos ramos (esquerdo r=-0,73 e direito r=-0,68) e côndilos (esquerdo r=-0,53 e direito r=-0,46). Os deslocamentos médios sofridos pelas estruturas do lado esquerdo foram suavemente maiores do que no direito. Correlações dos deslocamentos ocorridos entre T1-T2 e T2-T3 mostraram que: os deslocamentos dos côndilos esquerdos com a cirurgia foram negativamente correlacionados às adaptações pós-cirúrgicas destes (r=-0,51); e que o deslocamento da porção superior do ramo esquerdo com a cirurgia foi correlacionado à adaptação pós-cirúrgica ocorrida nos bordos posteriores (r=0,39) e côndilos do mesmo lado (r=0,39). Pode-se concluir que: (1) os deslocamentos causados pela cirurgia foram de modo geral estáveis no acompanhamento de 1 ano, mas identificou-se uma considerável variação individual; (2) as mudanças pós-cirúrgicas na posição do mento foram correlacionadas a adaptações sofridas pelos côndilos e bordos posteriores dos ramos; e que (3) deslocamentos suavemente maiores causados pela cirurgia nas estruturas do lado esquerdo levaram a maiores adaptações pós-cirúrgicas no segmento proximal deste lado.

Relações filogenéticas dos tubarões-martelo (Elasmobranchii: Sphyrnidae) com ênfase em morfologia

A cabeça lateralmente expandida é a principal sinapomorfia da família Sphyrnidae, a qual compreende todos os tubarões-martelo. Apesar de haver trabalhos abordando esta família, sua anatomia interna tem sido negligenciada como fonte de caracteres para serem utilizados na taxonomia e filogenia dos Sphyrnidae, em especial acerca de seu cefalofólio. Além disso, outros caracteres permanecem pouco estudados na família, tais como os referentes à anatomia dentária, dentículos dérmicos e sistema de poros sensoriais do cefalofólio. As relações filogenéticas entre os Sphyrnidae, e desta família entre os demais Carcharhiniformes, ainda é controversa como sua taxonomia. As poucas hipóteses filogenéticas conhecidas, baseadas em morfologia, não foram testadas sob critérios sistemáticos. Já as poucas hipóteses moleculares existentes foram testadas mas são ainda mais controversas. O presente estudo apresenta uma revisão anatômica e taxonômica dos Sphyrnidae, construindo uma matriz de caracteres mais robusta para testar as relações filogenéticas entre os Sphyrnidae, contando com 3 gêneros relacionados no grupo externo: Carcharhinus, Rhizoprionodon e Negaprion. Os resultados posicionam S. tiburo na base da família, e E. blochii e S. tudes compondo um dos clados mais derivados. Espécies de maior porte e cefalofólio mais expandido compõem um clado formado por S. mokarran + (S. lewini + S. zygaena), ao passo que as de menor porte e com cefalofolio mais arredondado formam um grupo polifilético. Rhizoprionodon acutus aparece como monofilético à família Sphyrnidae quando incluído fora do grupo externo. As árvores de consenso (Strictus, Semi-strictus, Majority-rule e Adams) apresentam os mesmos resultados. Os caracteres cranianos, sensoriais e de dentículo dérmico são os que mais suportaram os diversos clados. Após a revisão taxonômica da família, a filogenia com base em morfologia apresentou-se mais consistente e clara, embora controversa aos dados moleculares.

Diversidade, diferenciação e biogeografia de pequenos mamíferos não-voadores na Mata Atlântica ao norte do rio São Francisco Centro de Endemismo Pernambuco

As florestas tropicais brasileiras (Amazônia e a Mata Atlântica) possuem alta diversidade de espécies e atualmente estão separadas por um cinturão de vegetação aberta. Parte deste cinturão é ocupada pela Caatinga, onde se encontram os Brejos de Altitude, testemunhos das conexões históricas entre a Mata Atlântica e a Amazônia. O Centro de Endemismos Pernambuco (CEPE) é a unidade biogeográfica que compõe a Mata Atlântica ao norte do rio São Francisco e contém diversos táxons endêmicos. Esta região apresenta uma mastofauna compartilhada com a Amazônia, devido às conexões existentes durante o Cenozóico. A presença do rio São Francisco em seu limite sul pode atuar como barreira ao fluxo gênico e explicar os endemismos encontrados no CEPE. Contrastando com sua situação peculiar, a mastofauna do CEPE ainda carece de estudos aprofundados sobre a identificação de suas espécies, padrões geográficos e relações filogenéticas. Revisões recentes têm identificado espécies diferentes ao norte e ao sul do rio São Francisco, mas poucos trabalhos têm proposto hipóteses biogeográficas para o CEPE. Para ampliar o conhecimento sobre a identidade e distribuição geográfica dos pequenos mamíferos do CEPE e sua estrutura filogeográfica, foram realizados levantamentos de espécies e análises de diversidade genética e morfométrica para algumas espécies. Os levantamentos consistiram de visitas às coleções científicas a fim de identificar as espécies ocorrentes no CEPE e excursões de coleta com 5 a 17 noites consecutivas em 12 localidades ao longo do CEPE, que totalizaram 64691 armadilhas noites e resultaram na coleta de 476 exemplares de 31 espécies. As espécies foram identificadas com base na morfologia externa e craniana e por análises citogenéticas. Para investigar a biogeografia do CEPE, análises de genética de populações, filogeográficas e morfométricas foram realizadas para os marsupiais Caluromys philander, Didelphis aurita, Marmosa murina, Metachirus nudicaudatus e os roedores Akodon cursor, Oecomys catherinae e Rhipidomys mastacalis para avaliar a existência de diferenciação nas populações do CEPE e suas relações com as linhagens Amazônicas e Atlânticas. Estes resultados mostraram que a diversificação dos pequenos mamíferos do CEPE ocorreu tanto no Terciário quanto no Quaternário. Algumas populações, como em Caluromys philander e Oecomys catherinae, mostraram afinidades com linhagens amazônicas, enquanto outras, como em Metachirus nudicaudatus e Rhipidomys mastacalis, apresentaram afinidades com linhagens atlânticas. Os pequenos mamíferos do CEPE apresentaram diferenciação em relação às suas linhagens irmãs, com algumas linhagens podendo tratar-se de espécies ainda não descritas (e.g. Didelphis aff. aurita e Rhipidomys aff. mastacalis). Esta diferenciação provavelmente foi causada pelos eventos cíclicos de flutuações climáticas que provocaram elevações no nível do mar e retração das florestas tropicais, isolando as populações do CEPE. Por fim, para auxiliar na identificação das espécies em novas coletas, de suas distribuições geográficas e de suas características citogenéticas e ecológicas, foi elaborado um guia reunindo todas as informações disponíveis sobre as espécies de pequenos mamíferos do CEPE.

Distribuição e conservação de Lonchophylla bokermanni Sazima, Vizotto & Taddei 1978 (CHIROPTERA: Phyllostomidae)

Lonchophylla bokermanniSazima, Vizotto & Taddei, 1978 é uma espécie de morcego nectarívoro de médio porte endêmica do sudeste brasileiro. Pouco se sabe sobre sua biologia e distribuição geográfica, e por isso mesmo é classificada pela União para Conservação da Natureza (IUCN) como Deficiente de Dados. Está, no entanto, na lista brasileira da fauna ameaçada de extinção, sendo considerada Vulnerável por apresentar distribuição restrita, populações pequenas e isoladas, e estar vivenciando uma rápida destruição de seus habitats.Uma das mais importantes lacunas no conhecimento sobre L. bokermanni é o seu padrão de distribuição geográfica. Esta espécie possui uma distribuição disjunta, com uma forma na porção interior de sua distribuição, restrita aos arredores de sua localidade tipo, e uma forma com uma distribuição mais ampla, entre a Serra do Mar e o litoral. Existe a possibilidade de que a forma costeira possa corresponder a uma espécie ainda não descrita, visto que possui antebraços menores e algumas medidas cranianasdiferentes em relação a forma do interior.Nesta dissertação procuro gerar dados quantitativos mínimos necessários para determinar o status de conservação de L. bokermanni segundo os critérios da IUCN. Tendo em vista as incertezas taxonômicas, sempre que possível as análises foram feitas com três conjuntos de dados: i) todos os registros de ocorrência, assumindo que representam uma única espécie, ii) apenas com os dados da forma do interior, assumindo que representam L. bokermanni, e iii) apenas com os dados da forma costeira, assumindo que representam uma nova espécie. No primeiro capítulo foram identificadas áreas prioritárias para a busca de novas populações de L. bokermanni Essas áreas apresentam as condições climáticas e altitudinais típicas para a espécie, mantêm sua cobertura florestal, têm poucos inventários de quirópteros e estão fora da área de distribuição conhecida da espécie. O capítulo também apresenta o resultado da busca em campo por novas populações da espécie em três destas áreas prioritárias, ao sul da distribuição conhecida. No segundo capítulo a probabilidade de detecção e ocupação de Lonchophylla bokermanni foi modelada em escala regional e local, utilizando covariáveis ambientais e metodológicas que podem explicar os padrões encontrados. O grau de incerteza na distribuição conhecida da espécie foi avaliado, e estimou-se o esforço mínimo necessário para termos confiançana ausência da espécie em uma localidade. No terceiro capítulo a informação apresentada nos capítulos anteriores foi utilizada para determinar o status de conservação de L. bokermanni (segundo o critério de Extensão de Ocorrência da IUCN), discutir o estado atual de conhecimento sobre a espécie e as consequências de possíveis mudanças taxonômicas para seu status de conservação.

Variações cranianas em Tursiops truncatus (Mammalia: Certartiodactyla) em diferentes localidades dos oceanos, com ênfase na costa sul-americana: uma abordagem pela técnica de morfometria geométrica

Os delfinídeos são os cetáceos mais ecologicamente diversos, ocorrendo numa ampla faixa de latitudes, em águas oceânicas e costeiras, incluindo regiões estuarinas e dulcícolas. O cenário taxonômico é especialmente confuso no gênero Tursiops, uma vez que grande parte das formas tem sido sinonimizadas na espécie Tursiopstruncatus. No entanto, estudos recentes sugerem que o gênero Tursiops seja polifilético. O golfinho-nariz-de-garrafa,T.truncatus, ocorre tanto em águas costeiras quanto oceânicas, em todas as regiões tropicais e temperadas. A espécie T. truncatus é tida como polimórfica e tal característica a torna alvo de acirradas discussões acerca do que são variações regionais ou diferentes entidades taxonômicas. O objetivo do presente estudo foi analisar a variabilidade morfológica de T. truncatus em distintas regiões oceânicas, buscando fornecer informações que permitam embasar os argumentos para futuras discussões taxonômicas que envolvem o gênero. Para isso, foi feita análise de Morfometria Geométrica em 2-D de crânios em vistas dorsal e lateral de espécimes que ocorrem nos oceanos Pacífico Norte Oriental, Atlântico Norte Ocidental, Atlântico Sul Ocidental, Atlântico Norte Oriental, Atlântico Sul Oriental e Índico. Foram encontradas diferenças significativas em todo o material analisado, incluindo diferenças entre exemplares reconhecidos como T. gephyreus e T. truncatus na costa Atlântica da América do Sul. As variações cranianas encontradas possuem relação com o tipo de ambiente em que os diferentes grupos ocorrem e podem estar relacionadas com a forma de forrageio, captura de presa e ao sistema de ecolocalização. Além disso, as variações na costa Atlântica da América do Sul podem ser explicadas pelo possível reconhecimento de duas espécies nessa região

A method to improve size estimates of walleye pollock (Theragra chalcogramma) Atka mackerel (Pleurogrammus monopterygius) consumed by pinnipeds: digestion correction factors applied to bones and otoliths recovered in scats

The lengths of otoliths and other skeletal structures recovered from the scats of pinnipeds, such as Steller sea lions (Eumetopias jubatus), correlate with body size and can be used to estimate the length of prey consumed. Unfortunately, otoliths are often found in too few scats or are too digested to usefully estimate prey size. Alternative diagnostic bones are frequently recovered, but few bone-size to prey-size correlations exist and bones are also reduced in size by various degrees owing to digestion. To prevent underestimates in prey sizes consumed techniques are required to account for the degree of digestion of alternative bones prior to estimating prey size. We developed a method (using defined criteria and photo-reference material) to assign the degree of digestion for key cranial structures of two prey species: walleye pollock (Theragra chalcogramma) and Atka mackerel (Pleurogrammus monopterygius). The method grades each structure into one of three condition categories; good, fair or poor. We also conducted feeding trials with captive Steller sea lions, feeding both fish species to determine the extent of erosion of each structure and to derive condition-specific digestion correction factors to reconstruct the original sizes of the structures consumed. In general, larger structures were relatively more digested than smaller ones. Mean size reduction varied between different types of structures (3.3−26.3%), but was not influenced by the size of the prey consumed. Results from the observations and experiments were combined to be able to reconstruct the size of prey consumed by sea lions and other pinnipeds. The proposed method has four steps: 1) measure the recovered structures and grade the extent of digestion by using defined criteria and photo-reference collection; 2) exclude structures graded in poor condition; 3) multiply measurements of structures in good and fair condition by their appropriate digestion correction factors to derive their original size; and 4) calculate the size of prey from allometric regressions relating corrected structure measurements to body lengths. This technique can be readily applied to piscivore dietary studies that use hard remains of fish.

Sizes of walleye pollock (Theragra chalcogramma) and Atka mackerel (Pleurogrammus monopterygius) consumed by the western stock of Steller sea lions (Eumetopias jubatus) in Alaska from 1999 to 2000

Prey-size selectivity by Steller sea lions (Eumetopias jubatus) is relevant for understanding the foraging behavior of this declining predator, but studies have been problematic because of the absence and erosion of otoliths usually used to estimate fish length. Therefore, we developed regression formulae to estimate fish length from seven diagnostic cranial structures of walleye pollock (Theragra chalcogramma) and Atka mackerel (Pleurogrammus monopterygius). For both species, all structure measurements were related with fork length of prey (r2 range: 0.78−0.99). Fork length (FL) of walleye pollock and Atka mackerel consumed by Steller sea lions was estimated by applying these regression models to cranial structures recovered from scats (feces) collected between 1998 and 2000 across the range of the Alaskan western stock of Steller sea lions. Experimentally derived digestion correction factors were applied to take into account loss of size due to digestion. Fork lengths of walleye pollock consumed by Steller sea lions ranged from 3.7 to 70.8 cm (mean=39.3 cm, SD=14.3 cm, n=666) and Atka mackerel ranged from 15.3 to 49.6 cm (mean=32.3 cm, SD=5.9 cm, n=1685). Although sample sizes were limited, a greater proportion of juvenile (≤20 cm) walleye pollock were found in samples collected during the summer (June−September) on haul-out sites (64% juveniles, n=11 scats) than on summer rookeries (9% juveniles, n=132 scats) or winter (February−March) haul-out sites (3% juveniles, n=69 scats). Annual changes in the size of Atka mackerel consumed by Steller sea lions corresponded to changes in the length distribution of Atka mackerel resulting from exceptionally strong year classes. Considerable overlap (>51%) in the size of walleye pollock and Atka mackerel taken by Steller sea lions and the sizes of these species caught by the commercial trawl fishery were demonstrated.