White Cane Update, Fall 2007

The White Cane Update newsletter includes information about the latest happenings at the Iowa Department for the Blind.

White Cane Update, Winter 2008

The White Cane Update newsletter includes information about the latest happenings at the Iowa Department for the Blind.

Proton T1 relaxation times of metabolites in human occipital white and gray matter at 7 T.

Proton T1 relaxation times of metabolites in the human brain have not previously been published at 7 T. In this study, T1 values of CH3 and CH2 group of N-acetylaspartate and total creatine as well as nine other brain metabolites were measured in occipital white matter and gray matter at 7 T using an inversion-recovery technique combined with a newly implemented semi-adiabatic spin-echo full-intensity acquired localized spectroscopy sequence (echo time = 12 ms). The mean T1 values of metabolites in occipital white matter and gray matter ranged from 0.9 to 2.2 s. Among them, the T1 of glutathione, scyllo-inositol, taurine, phosphorylethanolamine, and N-acetylaspartylglutamate were determined for the first time in the human brain. Significant differences in T1 between white matter and gray matter were found for water (-28%), total choline (-14%), N-acetylaspartylglutamate (-29%), N-acetylaspartate (+4%), and glutamate (+8%). An increasing trend in T1 was observed when compared with previously reported values of N-acetylaspartate (CH3 ), total creatine (CH3 ), and total choline at 3 T. However, for N-acetylaspartate (CH3 ), total creatine, and total choline, no substantial differences compared to previously reported values at 9.4 T were discernible. The T1 values reported here will be useful for the quantification of metabolites and signal-to-noise optimization in human brain at 7 T. Magn Reson Med 69:931-936, 2013. © 2012 Wiley Periodicals, Inc.

A Hull and White formula for a general stochastic volatility jump-diffusion model with applications to the study of the short-time behavior of the implied volatility

In this paper, generalizing results in Alòs, León and Vives (2007b), we see that the dependence of jumps in the volatility under a jump-diffusion stochastic volatility model, has no effect on the short-time behaviour of the at-the-money implied volatility skew, although the corresponding Hull and White formula depends on the jumps. Towards this end, we use Malliavin calculus techniques for Lévy processes based on Løkka (2004), Petrou (2006), and Solé, Utzet and Vives (2007).

Novas Pragas Agrícolas na Ilha de São Nicolau - Cabo Verde - Tuta absoluta (Meyrick) (Lep - Gelechiidae) e Bactrocera invadens (Drew, Tsuruta & White) (Dipt - Tephritidae)

Em algumas das ilhas do Arquipélago de Cabo Verde entraram, nos últimos dois anos, espécies invasoras que constituem pragas de culturas agrícolas e que têm apresentado elevada repercussão económica. Entre elas contam-se a traça do tomateiro, Tuta absoluta (Meyrick) (Lepidoptera: Gelechidae) e Bactrocera invadens (Drew, Tsuruta & White) (Diptera: Tephritidae). Com o objectivo de avaliar a presença destas pragas na ilha de São Nicolau, foram instaladas armadilhas com atractivos em quatro zonas com bananeiras (Ribeira Prata, Fajã, Maiama e Campo de Preguiça) para a monitorização da mosca da fruta. Foram também instaladas ensaios em seis parcelas de tomateiro para a comparação de estratégias de protecção contra T. absoluta, armadilha com feromona sexual para captura em massa em conjunto com Bacillus thuringiensis e tratamento com deltametrina. Das quatro zonas monitorizadas, B. invadens só foi encontrada no Vale da Fajã. No que diz respeito a T. absoluta, fez-se a comparação entre a população presente em três estratos do tomateiro e não se encontraram diferenças significativas. As estratégias de protecção contra T. absoluta também não diferiram significativamente no que se refere ao número de minas nas folhas e frutos furados. Nesidiocoris tenuis foi identificado como inimigo natural de T. absoluta presente na ilha.

Nyssomyia intermedia (Lutz & Neiva) and Nyssomyia neivai (Pinto) (Diptera, Psychodidae, Phlebotominae) in a sympatric area: seasonal and nocturnal hourly rhythm in black and white modified Shannon traps

Captures with black and white Shannon traps were undertaken to identify aspects of the behavior of the two cryptic and sympatric species implicated as vectors of cutaneous leishmaniasis, Nyssomyia intermedia (Lutz & Neiva, 1912) and Nyssomyia neivai (Pinto, 1926). The traps were installed side by side, monthly, from July 2001 to June 2002, from 18 to 07 hours, in a peridomicile of Iporanga municipality, state of São Paulo, Brazil. A total of 2,142 specimens were captured, Ny. intermedia (47.4%) and Ny. neivai (50.5%). The white trap was more attractive to both sexes of both species. Males of Ny. neivai predominated (70%) over those of Ny. intermedia on the two traps; on the black trap, the females of Ny. intermedia predominated (63.3%) over those of Ny. neivai (36.7%). Seventy percent of the specimens of both species were captured between 18 and 24 h. Females of Ny. intermedia presented the highest peak at 19-20 h, and those of Ny. neivai at 20-21 h. The highest hourly average for females of Ny. intermedia on the black trap occurred in the winter and that for males in the summer. For Ny. neivai, both sexes predominated in the summer. The two species probably transmit the cutaneous leishmaniasis in the area due to their great predominance.

A new species of Eufriesea Cockerell (Hymenoptera, Apidae, Euglossina) from northeastern Brazil

A new species of Eufriesea Cockerell (Hymenoptera, Apidae) from northeastern Brazil. Eufriesea pyrrhopyga sp. nov. a short-tongued Eufriesea is described as a new species. It can be easily recognized for its predominantly violet lower frons and thorax, violet tergum 1 contrasting with the strong reddish coloration on the lateral portions of terga 2 to 4 and on entire terga 5 and 6, and head pubescence with contrasting colors, white on the lower two-thirds of the face and black on upper frons and vertex. This new species, collected in Recife (Pernambuco, Brazil), apparently is restricted to the Pernambuco endemic center, and seems to be highly endangered.

Mineralogical, petrographic and geochemical characterisation of white and coloured Iberian marbles in the context of the provenancing of some artefacts from Thamusida (Kenitra, Morocco)

A multi-analytical study has been carried out on a collection of white and coloured Iberian marbles. A total of 135 marble specimens were collected in Spain and Portugal from the Betic chain (Alhaurin de la Torre, Mijas, Macael), Ossa Morena (Alconera, Almaden de la Plata and Viana do Alentejo), and the Estremoz Anticline (Bencatel, Borba and Estremoz) areas. X-ray diffractometry and carbon and oxygen stable isotope analysis were carried out on these samples; 38 samples were also investigated by optical and scanning electron microscopy. The results provide a set of diagnostic parameters that allow discriminating the sampled marble quarries. The carbonate minerals composition is distinctive for the Mijas and Alhaurin de la Torre marbles; the isotopic analysis allows discriminating also between these two dolomitic marble quarries. The Ossa Morena and Estremoz Anticline marbles share a similar stable isotope composition; the accessory mineral content, the maximum grain size (MGS) and the fabric are particularly useful in the distinction between them. In the framework of archaeometric provenance studies on Thamusida (Kenitra, Morocco) Roman marble artefacts, a specific comparison between this new Iberian database and archaeological findings has been carried out. The hypothesis of commercial exchanges between the Iberian regions and Roman Morocco is supported by the results of the provenance study, which suggested the Almaden de la Plata and Mijas quarries as possible sources of raw materials for the production of archaeological artefacts.

Analysis of digestive tract content of the larvae of Polybia scutellaris (White) (Hymenoptera, Vespidae)

Polybia scutellaris (White, 1841) is a social wasp of biological interest for its role as pollinator and maybe as biological control agent of sanitary and agricultural pests. This study examines the digestive tract contents of the larvae of P. scutellaris from four nests in Magdalena (Buenos Aires province, Argentina). Contents included both animal (arthropod parts) and plant (pollen, leaf and fruit epidermis) parts. The pollen content analysis showed that the wasps visited 19 different taxa of plants during the last active period of the colony before the nests had been collected. The range of sources used by P. scutellaris allows us characterizing the species as a generalist flower visitor. Wasps visited both native and exotic plants located nearby the nest. Most of the epidermal plant remains found in the larval digestive tract belonged to Malvaceae, a family not exploited by the studied colonies as pollen source.

Interaction between tobacco and alcohol use and the risk of head and neck cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium.

BACKGROUND: The magnitude of risk conferred by the interaction between tobacco and alcohol use on the risk of head and neck cancers is not clear because studies have used various methods to quantify the excess head and neck cancer burden. METHODS: We analyzed individual-level pooled data from 17 European and American case-control studies (11,221 cases and 16,168 controls) participating in the International Head and Neck Cancer Epidemiology consortium. We estimated the multiplicative interaction parameter (psi) and population attributable risks (PAR). RESULTS: A greater than multiplicative joint effect between ever tobacco and alcohol use was observed for head and neck cancer risk (psi = 2.15; 95% confidence interval, 1.53-3.04). The PAR for tobacco or alcohol was 72% (95% confidence interval, 61-79%) for head and neck cancer, of which 4% was due to alcohol alone, 33% was due to tobacco alone, and 35% was due to tobacco and alcohol combined. The total PAR differed by subsite (64% for oral cavity cancer, 72% for pharyngeal cancer, 89% for laryngeal cancer), by sex (74% for men, 57% for women), by age (33% for cases <45 years, 73% for cases >60 years), and by region (84% in Europe, 51% in North America, 83% in Latin America). CONCLUSIONS: Our results confirm that the joint effect between tobacco and alcohol use is greater than multiplicative on head and neck cancer risk. However, a substantial proportion of head and neck cancers cannot be attributed to tobacco or alcohol use, particularly for oral cavity cancer and for head and neck cancer among women and among young-onset cases.

Pineus boerneri Annand, 1928 (Hemiptera, Adelgidae) - a new species to Brazil: morphology of eggs, nymphs and adults

Pineus boerneri Annand, 1928 (Hemiptera, Adelgidae) _ a new species to Brazil: morphology of eggs, nymphs and adults. Pineus boerneri represents the first Adelgidae species recorded in Brazil. This aphid species forms extensive colonies on branches and trunk of Pinus spp., with apterous oviparous females, eggs and nymphs covered with white wax. The aim of this research is to study the morphology of eggs, nymphs, and adults to provide useful data for species identification in order to solve taxonomic issues. The study was based on morphometric data and optical and scanning electron microscopy images. First instar nymphs are active and can be easily distinguished from the others by their elongate minute yellowish body; well developed legs bearing a pair of sensorial setae at the apex of the second tarsomere; and antenna with three segments with a large rhinarium and distinct apical setae on the last segment. From the second to the fourth instar, nymphs are sessile, with round red body; they loose the third antennal segment and its sensorial structures, as well as the setae on the second tarsomere. The oviparous female is reddish-brown, with round body with about 0.76 mm diameter; legs reduced; antennae one-segmented; ovipositor distinct; numerous wax glands are present, mainly on the head. Accurate characterization of the species and distinction of the nymphal instars of P. boerneri were made possible by canonical analysis of morphometric data and morphological characters.

Structural covariance of superficial white matter in mild Alzheimer's disease compared to normal aging.

INTRODUCTION: Interindividual variations in regional structural properties covary across the brain, thus forming networks that change as a result of aging and accompanying neurological conditions. The alterations of superficial white matter (SWM) in Alzheimer's disease (AD) are of special interest, since they follow the AD-specific pattern characterized by the strongest neurodegeneration of the medial temporal lobe and association cortices. METHODS: Here, we present an SWM network analysis in comparison with SWM topography based on the myelin content quantified with magnetization transfer ratio (MTR) for 39 areas in each hemisphere in 15 AD patients and 15 controls. The networks are represented by graphs, in which nodes correspond to the areas, and edges denote statistical associations between them. RESULTS: In both groups, the networks were characterized by asymmetrically distributed edges (predominantly in the left hemisphere). The AD-related differences were also leftward. The edges lost due to AD tended to connect nodes in the temporal lobe to other lobes or nodes within or between the latter lobes. The newly gained edges were mostly confined to the temporal and paralimbic regions, which manifest demyelination of SWM already in mild AD. CONCLUSION: This pattern suggests that the AD pathological process coordinates SWM demyelination in the temporal and paralimbic regions, but not elsewhere. A comparison of the MTR maps with MTR-based networks shows that although, in general, the changes in network architecture in AD recapitulate the topography of (de)myelination, some aspects of structural covariance (including the interhemispheric asymmetry of networks) have no immediate reflection in the myelination pattern.

Fetal dose reduction in head and neck radiotherapy of a pregnant woman.

BACKGROUND AND PURPOSE: A pregnant woman was referred for post-operative radiotherapy of a malignant schwannoma in the head and neck region. A best-treatment plan was devised in order to minimize the fetal dose. MATERIAL AND METHODS: The fetal dose resulting from radiological examinations was determined according to international protocols, that resulting from radiotherapy was calculated according to Recommendation 36 of the American Association of Physicists in Medicine (AAPM) Task Group. Pre-treatment dosimetry was performed with an anthropomorphic phantom. Several alternative treatment plans were evaluated. The use of a multileaf collimator (MLC) and a virtual wedge (VW) was compared to cerrobend blocks (CB) and physical wedge (PW). In-vivo dosimetry was performed using a vaginal probe containing thermoluminescent dosimeters (TLD). RESULTS: The total fetal dose resulting from diagnostic and radiotherapy procedures was estimated to be 36 mGy. The technique based on MLC and VW was elected for patient treatment. Measurements for this configuration resulted in afetal dose reduction of 82%. The shielding of the patient's abdomen further reduced the fetal dose by 42%. CONCLUSION: The use of VW and MLC for the treatment of a pregnant woman is highly recommended. Each case should be individually studied with pre-treatment and in-vivo dosimetry.

Quantitative Assessment of T1 Relaxation and Diffusion as a Prognostic Tool for Brain Development: A Longitudinal Preliminary Study on Preterm Babies

BACKGROUND: Despite major advances in care of premature infants, survivors exhibit mild cognitive deficits in around 40%. Beside severe intraventricular haemorrhages (IVH) and cystic periventricular leucomalacia (PVL), more subtle patterns such as grade I and II IVH, punctuate WM lesions and diffuse PVL might be linked to the cognitive deficits. Grey matter disease is also recognized to contribute to long-term cognitive impairment.¦OBJECTIVE: We intend to use novel MR techniques to study more precisely the different injury patterns. In particular MP2RAGE (magnetization prepared dual rapid echo gradient) produces high-resolution quantitative T1 relaxation maps. This contrast is known to reflect tissue anomalies such as white matter injury in general and dysmyelination in particular. We also used diffusion tensor imaging, a quantitative technique known to reflect white matter maturation and disease.¦DESIGN/METHODS: All preterm infants born under 30 weeks of GA were included. Serial 3T MR-imaging using a neonatal head-coil at DOL 3, 10 and at term equivalent age (TEA), using DTI and MP2RAGE sequences was performed. MP2RAGE generates a T1 map and allows calculating the relaxation time T1. Multiple measurements were performed for each exam in 12 defined white and grey matter ROIs.¦RESULTS: 16 patients were recruited: mean GA 27 2/7 w (191,2d SD±10,8), mean BW 999g (SD±265). 39 MRIs were realized (12 early: mean 4,83d±1,75, 13 late: mean 18,77d±8,05 and 14 at TEA: 88,91d±8,96). Measures of relaxation time T1 show a gradual and significant decrease over time (for ROI PLIC mean±SD in ms: 2100.53±102,75, 2116,5±41,55 and 1726,42±51,31 and for ROI central WM: 2302,25±79,02, 2315,02±115,02 and 1992,7±96,37 for early, late and TEA MR respectively). These trends are also observed in grey matter area, especially in thalamus. Measurements of ADC values show similar monotonous decrease over time.¦CONCLUSIONS: From these preliminary results, we conclude that quantitative MR imaging in very preterm infants is feasible. On the successive MP2RAGE and DTI sequences, we observe a gradual decrease over time in the described ROIs, representing the progressive maturation of the WM micro-structure and interestingly the same evolution is observed in the grey matter. We speculate that our study will provide normative values for T1map and ADC and might be a predictive factor for favourable or less favourable outcome.

The Effect of Amifostine on Acute and Late Radiation Side Effects in Head and Neck Cancer Patients

Objective: We aimed to investigate the effect of amifostine on acute and late side effects, and its tolerability in head and neck cancer patients treated with radiotherapy (RT). Material and Methods: The study included 87 patients with primary head and neck cancers and cervical lymph node metastases from unknown primary cancers treated with RT alone or combined with chemotherapy (CT). Forty-one patients (47%) received amifostine combined with RT (ART group) and 46 patients (52%) received RT without amifostine (RT group). The patients were evaluated every week during the treatment and at month 1 and 2 after the completion of RT for acute side effects and month 3, 6, 9, 12, and 24 after the treatment for late side effects according to SOMA/LENT scale. Amifostine was administered prior to RT, along with anti-emetic prophylaxis. The two groups were compared with the Student's t and Mann-Whitney U and Chi-square tests. Results: The ART group had significantly less toxicity (grade! 1 mucositis, grade 2 fibrosis) than patients in the RT group (p=0.001, p=0.03, respectively). At week 3 of RT grade 2 mucositis developed in two patients (5%) in the ART group and 10 patients (22%) in the RT group (p=0.02). The protective effect of amifostine on skin reactions developed at week 4 of RT (p=0.05). Grade 3 xerostomia at 9, 12, and 15 months of follow-up (p=0.02, p=0.02, and p=0.02, respectively), grade 2 xerostomia at 18 and 24 months (p=0.02 and p=0.01, respectively) and fibrosis at 15, 18 and 24 months (p=0.05, p=0.02 and p=0.02, respectively) decreased markedly in the ART group compared with the RT group. Emesis was the most common adverse effect of amifostine. Conclusion: Daily administration of amifostine during RT was effective in avoiding late grade 2-3 xerostomia, as well as grade 2 fibrosis.