Gonad development in females of fiddler crab Uca rapax (Crustacea, Brachyura, Ocypodidae) using macro and microscopic techniques

The morphology of the ovaries in Uca rapax (Smith, 1870) was described based on macroscopic and microscopic analysis. Females were collected in Itamambuca mangrove, Ubatuba, state of São Paulo, Brazil. In the laboratory, 18 females had their ovaries removed and prepared for histology. Each gonad developmental stage was previously determined based on external and macroscopic morphology and afterwards each stage was microscopically described. The ovaries of U. rapax showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with six ovarian developmental stages: immature, rudimentary, developing, developed, advanced and spent. During the vitellogenesis, the amount of oocytes in secondary stage increases in the ovary, resulting in a change in coloration of the gonad. Oogonias, primary oocytes, secondary oocytes and follicular cells were histologically described and measured. In female’s ovaries of U. rapax the modifications observed in the oocytes during the process of gonad maturation are similar to descriptions of gonads of other females of brachyuran crustaceans. The similarities are specially found in the morphological changes in the reproductive cells, and also in the presence and arrange of follicle cells during the process of ovary maturation. When external morphological characteristics of the gonads were compared to histological descriptions, it was possible to observe modifications that characterize the process in different developmental stages throughout the ovarian cycle and, consequently, the macroscopic classification of gonad stages agree with the modifications of the reproductive cells.

Oviposition behavior of wild Zabrotes subfasciatus (Coleoptera, Chrysomelidae) females deprived of the host Phaseolus vulgaris (Fabaceae)

The insects oviposition behavior is fundamental to study population dynamics, life history evolution, insect-plant and parasitoid-host interactions. Zabrotes subfasciatus (Boheman, 1833) females oviposition behavior in the presence and absence of a host is unknown. The main objective of this study was to describe in detail the oviposition behavior of host deprived or non-deprived females, and observe how the several situations of deprivation (days without host) influence oviposition. Six groups were assembled, three deprived of the host (for 2, 5 and 8 days) and three control groups (with host), each containing one newly-emerged couple (0-24h) of wild Z. subfasciatus, The non-deprived (control) groups received the hosts every day (5 bean seeds Phaseolus vulgaris (Fabaceae)) and the others were deprived for 2, 5 and 8 days, respectively. For each group 12 repetitions were made. Consequently, 12 couples were host deprived during two days, 12 couples were host deprived during five days and 12 couples were host deprived during eight days. When the seeds of the deprived groups were added the experiments started. There was a control group for each deprived group. The experiments and the insects were maintained at constant temperature 29 ± 2ºC and 70-80% relative humidity. At 15 minutes interval, the number of times the females manifested the different categories of behavior was observed (frequency). The behavior categories were: rest inside the box, locomotion, resource exploration (seeds), copulation and oviposition. The deprived females stayed most of the time in contact with the host to carry out oviposition, while the non-deprived (control) females spent most of the time at rest. This was observed in all the deprivation times. The results show that host deprivation influences the oviposition behavior of the studied species and also shows the flexibility in the oviposition strategies that these females present when the environment changes (absence and presence of resources)

First nesting record of the Bay-Capped Wren-Spinetail Spartonoica maluroides (Aves, Furnariidae) in Brazil, with nest and nestling descriptions and notes on breeding behavior

The only breeding record of Spartonoica maluroides (d'Orbigny & Lafresnaye, 1837) for Brazil is based on the observation of a fledgling in southern Rio Grande do Sul in January 1976. On 7 December 2005 we discovered a nest containing three nestlings at the southeastern end of Lagoa Pequena, municipality of Pelotas, Rio Grande do Sul. The nest was concealed at the base of a cavity in a Spartina densiflora (Poaceae) tussock located at the edge of a saltmarsh. The nest was built of fine pieces of dead Scirpus olneyi (Cyperaceae) and S. densiflora leaves firmly interlaced to the internal leaves of the tussock. Live leaves of S. densiflora lining the cavity comprised a substantial part of the nest's architecture, forming most of its upper lateral walls and roof. The lower section was more elaborate, resembling a deep cup and forming a distinct incubation chamber. Adults reached the nest's interior through an irregular apical opening amidst the leaves. The nest was 244 mm high and 140 mm wide. The incubation chamber had an external diameter of 138.5 mm, an internal diameter of 79.4 mm and was 86 mm deep. It was lined with fine leaves and white plant fibers. Nestlings were five to six days old. A total of 107 neossoptiles restricted to the capital, spinal and alar tracts were recorded in one nestling. The distribution of neossoptiles in the ocular region of S. maluroides forms a distinct pattern which can be typical of Furnariidae and related families. Two adults attended the nest, bringing small insects to the nestlings and removing fecal sacs. We recorded at least 74 visits to the nest during a ca. 6 h period during an afternoon. The average number of visits per hour was 12.8 ± 1.3. An adult bird spent on average 0.7 ± 0.56 minutes inside the nest attending nestlings. The nest remained unattended on average for 3.61 ± 3.13 minutes. The hour of the day had no influence on the amount of time spent by an adult in the nest or away from it. We returned to the area on 15 December 2005 and found the nest abandoned. Observations confirm that S. maluroides is a resident breeder in southern Brazil and that the saltmarshes of the Lagoa do Patos estuary are an important year-round habitat for the species. A nestling and the nest were collected to document the record.

Trophic ecology and foraging behavior of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata, Tropiduridae) in a caatinga area of northeastern Brazil

This study aimed to analyze the seasonal variation in diet composition and foraging behavior of Tropidurus hispidus (Spix, 1825) and T. semitaeniatus (Spix, 1825), as well as measurement of the foraging intensity (number of moves, time spent stationary, distance traveled and number of attacks on prey items) in a caatinga patch on the state of Rio Grande do Norte, Brazil. Hymenoptera/Formicidae and Isoptera predominated in the diet of both species during the dry season. Opportunistic predation on lepidopteran larvae, coleopteran larvae and adults, and orthopteran nymphs and adults occurred in the wet season; however, hymenopterans/Formicidae were the most important prey items. The number of food items was similar between lizard species in both seasons; however the overlap for number of prey was smaller in the wet season. Preys ingested by T. hispidus during the wet season were also larger than those consumed by T. semitaeniatus. Seasonal comparisons of foraging intensity between the two species differed, mainly in the wet season, when T. hispidus exhibited less movement and fewer attacks on prey, and more time spent stationary if compared to T. semitaeniatus. Although both lizards are sit-and-wait foragers, T. semitaeniatus is more active than T. hispidus. The diet and foraging behavior of T. hispidus and T. semitaeniatus overlap under limiting conditions during the dry season, and are segregative factors that may contribute to the coexistence of these species in the wet season.

Preparació de materials híbrids orgànico-inorgànics a partir de sals d'imidazoli

Estudi elaborat a partir d’una estada a l’ Ecole Nationale Supérieure de Chimie de Montpellier, França, durant 2006. S’han sintetitzat materials híbrids orgànico-inorgànics mitjançant el procés sol-gel i altres estratègies sintètiques. En alguns casos, s’ha intentat estructurar aquests materials, ja sigui per autoestructuració o per mitjà de tensioactius. Com a catalitzadors de les reaccions d'hidròlisi i policondensació s’han utilitzat àcids, bases i fluorurs. Els materials obtinguts s’han caracteritzat mitjançant diferents tècniques: BET (Brunauer-Emmett-Teller), TEM (microscopia electrònica de transmissió), SEM (microscòpia electrònica de rastreig), raigs X en pols , IR i RMN (ressonància magnètica nuclear) en estat sòlid. Amb aquests materials es pretén preparar catalitzadors heterogenis de Pd per reaccions d’acoblament creuat, i de Ru per reaccions de metàtesi. També s’han sintetitzat sals d'imidazoli amb cadenes hidrocarbonades llargues amb l'objectiu de preparar gels de sílice amb aquestes molècules atrapades dins la matriu inorgànica. Aquests materials s’utilitzaran com a organocatalitzadors i també es prepararan els corresponents catalitzadors de Pd per reaccions de Heck, Suzuki i Sonogashira. Les sals d’imidazoli s’han utilitzat com a tensioactius en la preparació de gels de sílice estructurats. Aquestes molècules han resultat ser cristalls líquids i s’han caracteritzar mitjançant DSC (differential scanning calorimetry), microscopia òptica i raigs X.

Financial incentives in academia: research versus development

This paper investigates the effects of monetary rewards on the pattern of research. We build a simple repeated model of a researcher capable to obtain innovative ideas. We analyse how the legal environment affects the allocation of researcher's time between research and development. Although technology transfer objectives reduce the time spent in research, they might also induce researchers to conduct research that is more basic in nature, contrary to what the skewing problem would presage. We also show that our results hold even if development delays publication.

License prices for financially constrained firms

It is often alleged that high auction prices inhibit service deployment. We investigate this claim under the extreme case of financially constrained bidders. If demand is just slightly elastic, auctions maximize consumer surplus if consumer surplus is a convex function of quantity (a common assumption), or if consumer surplus is concave and the proportion of expenditure spent on deployment is greater than one over the elasticity of demand. The latter condition appears to be true for most of the large telecom auctions in the US and Europe. Thus, even if high auction prices inhibit service deployment, auctions appear to be optimal from the consumers' point of view.

The role of behavior in the survival of Biomphalaria glabrata in biossays with the plant molluscicide Phytolacca dodecandra

This work examines the role of behavior in the survival of Biomphalaria glabrata exposed to 25, 50 75 and 100 mgl-1 of Phytolacca dodecandra. Time-lapse cinematography was used to quantify accurately the following parameters: (a) frequency of exits from the solution, (b) time spent out of the solution and (c) time elapsed until the first exit from the solution. These behavior patterns were statistically compared between surviving snails and those which later died. The proportion of surviving snails leaving the liquid medium was significantly higher than that of dying snails. In addition, the surviving group spent significantly more time out of the solution than the group which died, except for the 100 mgl-1 concentration. However, no significant difference was detected in the time elapsed until the first exit from the solution. It can be concluded that both the tendency to leave the P. dodecandra solutions, and the time spent out of them, contributed significantly to snail survival. Molluscicide bioassays should take into account the possibility that some behavior patterns of planorbids might contribute to the protection of the snails.

Ecology and neurophysiology of sleep in two wild sloth species

Study Objectives: Interspecific variation in sleep measured in captivity correlates with various physiological and environmental factors, including estimates of predation risk in the wild. However, it remains unclear whether prior comparative studies have been confounded by the captive recording environment. Herein we examine the impact of predation pressure on sleep in sloths living in the wild. Design: Comparison of two closely related sloth species, one exposed to predation and one free from predation. Setting: Panamanian mainland rainforest (predators present) and island mangrove (predators absent). Participants: Mainland (Bradypus variegatus, 5 males and 4 females) and island (Bradypus pygmaeus, 6 males) sloths. Interventions: None. Measurements and Results: EEG and EMG activity were recorded using a miniature data logger. Although both species spent between 9 and 10 hours per day sleeping, the mainland sloths showed a preference for sleeping at night, whereas island sloths showed no preference for sleeping during the day or night. EEG activity during NREM sleep showed lower low-frequency power, and increased spindle and higher frequency power in island sloths when compared to mainland sloths. Conclusions: In sloths sleeping in the wild, predation pressure influenced the timing of sleep, but not the amount of time spent asleep. The preference for sleeping at night in mainland sloths may be a strategy to avoid detection by nocturnal cats. The pronounced differences in the NREM sleep EEG spectrum remain unexplained, but might be related to genetic or environmental factors.

Pediatric emergencies admitted in the resuscitation room of a swiss university hospital.

OBJECTIVES: Pediatric resuscitation is an intense, stressful, and challenging process. The aim of this study was to review the life-threatening pediatric (LTP) emergencies admitted in a Swiss university hospital with regards to patients' demographics, reason for admission, diagnosis, treatment, significant events, critical incidents, and outcomes. METHODS: A retrospective observational cohort study of prospectively collected data was conducted, including all LTP emergencies admitted over a period of 2 years in the resuscitation room (RR). Variables, including indication for transfer, mode of prehospital transportation, diagnosis, and time spent in RR, were recorded. RESULTS: Of the 60,939 pediatric emergencies treated in our university hospital over 2 years, a total of 277 LTP emergencies (0.46%) were admitted in the RR. They included 160 boys and 117 girls, aged 6 days to 15.95 years (mean, 6.69 years; median, 5.06). A medical problem was identified in 55.9% (n = 155) of the children. Of the 122 children treated for a surgical problem, 35 (28.3%) went directly from the RR to the operating room. Hemodynamic instability was noted in 19.5% of all LTP emergencies, of which 1.1% benefited from O negative transfusion. Admission to the intensive care unit was necessary for 61.6% of the children transferred from another hospital. The average time spent in the RR was 46 minutes. The overall mortality rate was 7.2%. CONCLUSIONS: The LTP emergencies accounted for a small proportion of all pediatric emergencies. They were more medical than surgical cases and resuscitation measures because of hemodynamic instability were the most frequent treatment.

A behavioral study of alpha-1b adrenergic receptor knockout mice: increased reaction to novelty and selectively reduced learning capacities.

Knockout mice lacking the alpha-1b adrenergic receptor were tested in behavioral experiments. Reaction to novelty was first assessed in a simple test in which the time taken by the knockout mice and their littermate controls to enter a second compartment was compared. Then the mice were tested in an open field to which unknown objects were subsequently added. Special novelty was introduced by moving one of the familiar objects to another location in the open field. Spatial behavior and memory were further studied in a homing board test, and in the water maze. The alpha-1b knockout mice showed an enhanced reactivity to new situations. They were faster to enter the new environment, covered longer paths in the open field, and spent more time exploring the new objects. They reacted like controls to modification inducing spatial novelty. In the homing board test, both the knockout mice and the control mice seemed to use a combination of distant visual and proximal olfactory cues, showing place preference only if the two types of cues were redundant. In the water maze the alpha-1b knockout mice were unable to learn the task, which was confirmed in a probe trial without platform. They were perfectly able, however, to escape in a visible platform procedure. These results confirm previous findings showing that the noradrenergic pathway is important for the modulation of behaviors such as reaction to novelty and exploration, and suggest that this is mediated, at least partly, through the alpha-1b adrenergic receptors. The lack of alpha-1b adrenergic receptors in spatial orientation does not seem important in cue-rich tasks but may interfere with orientation in situations providing distant cues only.

A Foundation System and a State System - Private-School Implications on Welfare and Education Expenditure

This paper examines the effects of two different education - financing systems: a foundation system and a state system on the level and distribution of resources devoted to education in the presence of private schools. We use political economy approach where households differ in their level of income, and the central tax rate used to nance education is determined by a majority vote. Our analysis focuses on implications of allowing for a private-school option. To evaluate the importance of private schools we develop a computational model and calibrate it using USA data. The results reveal that the private school option is very important quantitatively in terms of welfare, total resources spent on education and equity.

Increasing respiratory dead space improves sleep disordered breathing and hypoxemia in patients with chronic mountain sickness

Background: Chronic mountain sickness (CMS), which is characterised by hypoxemia, erythrocytosis and pulmonary hypertension, is a major public health problem in high-altitude dwellers. The only existing treatment is descent to low altitude, an option that for social reasons almost never exists. Sleep disordered breathing may represent an underlying mechanism. We recently found that in mountaineers increasing the respiratory dead space markedly improves sleep disordered breathing. The aim of the present study was to assess the effects of this procedure on sleep disordered breathing in patients with CMS. Methods: In 10 male Bolivian high-altitude dwellers (mean ± SD age, 59 ± 9 y) suffering from CMS (haemoglobin >20 g/L) full night sleep recordings (Embletta, RespMed) were obtained in La Paz (3600 m). In random order, one night was spent with a 500 ml increase in dead space through a custom designed full face mask and the other night without it. Exclusion criteria were: secondary erythrocytosis, smoking, drug intake, acute infection, cardio- pulmonary or neurologic disease and travelling to low altitude in the preceding 6 months. Results: The major new finding was that added dead space dramatically improved sleep disordered breathing in patients suffering from CMS. The apnea/hypopnea index decreased by >50% (from 34.5 ± 25.0 to 16.8 ± 14.9, P = 0.003), the oxygen desaturation index decreased from 46.2 ± 23.0 to 27.2 ± 20.0 (P = 0.0004) and hypopnea index from 28.8 ± 20.9 to 16.3 ± 14.0 (P = 0.01), whereas nocturnal oxygen saturation increased from 79.8 ± 3.6 to 80.9 ± 3.0% (P = 0.009). The procedure was easily accepted and well tolerated. Conclusion: Here, we show for the very first time that an increase in respiratory dead space through a fitted mask dramatically improves nocturnal breathing in high-altitude dwellers suffering from CMS. We speculate that when used in the long-term, this procedure will improve erythrocytosis and pulmonary hypertension and offer an inexpensive and easily implementable treatment for this major public health problem.

Un estudi de les argumentacions d’estudiants anglesos i catalans en activitats de resolució de problemes no formals en ciències i de les estratègies didàctiques dels professors que afavoreixen l’argumentació a les classes

Una de les contribucions de la recerca sobre concepcions prèvies dels estudiants en ciències durant els darrers 25 anys ha estat mostrar la influència del context sociocultural dels nois i noies en les idees i concepcions que desenvolupen i mantenen des de la seva infància. Hi ha l’acord que algunes diferències en les concepcions poden dependre de la cultura social en la qual s’integren. Alguns investigadors també pensen que els esquemes argumentatius també poden ser influenciats per la cultura de les comunitats. Els contextos Català i Anglès semblen similars, ambdós formen part del context cultural de les societats desenvolupades; per tant, podem pensar que els esquemes argumentatius que els estudiants apliquen, poden tenir moltes similituds, però també importants diferències. Les dades analitzades provenen de les respostes escrites dels estudiants individuals i de les transcripcions de 8 grups de discussió sobre quatre tasques. L’anàlisi es fa a tres nivells: 1)comparació del nombre d’arguments entre tasques i entre països, 2) qualitativa i descriptiva comparació entre tipus d’esquemes argumentatius per tasques i per països i 3) explicació de tipus d’esquemes argumentatius que es donen molt, i identificació d’estructures argumentatives complexes que lliguen diversos esquemes en un argument més gran i que poden caracteritzar l’argumentació d’alguns grups (aplicant Toulmin) i que poden ser indicadors d’aspectes cooperatius i de canvis de punts de vista en les discussions. Els resultants ens indiquen que encara que els estudiants Catalans dediquen més temps a les discussions, la ratio nombre d’esquemes per unitat de temps és similar als dos països. S’han trobar algunes diferències entre tipus d'esquemes per països i per tasques, també que molts arguments es basen en valors i idees preconcebudes. S’han pogut identificar també algunes estructures argumentatives complexes no gaire comunes.

On the cost of rent-seeking by government bureaucrats in a Real-Business-Cycle framework

This paper studies the wasteful e ffect of bureaucracy on the economy by addressing the link between rent-seeking behavior of government bureaucrats and the public sector wage bill, which is taken to represent the rent component. In particular, public o fficials are modeled as individuals competing for a larger share of those public funds. The rent-seeking extraction technology in the government administration is modeled as in Murphy et al. (1991) and incorporated in an otherwise standard Real-Business-Cycle (RBC) framework with public sector. The model is calibrated to German data for the period 1970-2007. The main fi ndings are: (i) Due to the existence of a signi ficant public sector wage premium and the high public sector employment, a substantial amount of working time is spent rent-seeking, which in turn leads to signifi cant losses in terms of output; (ii) The measures for the rent-seeking cost obtained from the model for the major EU countries are highly-correlated to indices of bureaucratic ineffi ciency; (iii) Under the optimal scal policy regime,steady-state rent-seeking is smaller relative to the exogenous policy case, as the government chooses a higher public wage premium, but sets a much lower public employment, thus achieving a decrease in rent-seeking.