Variation In Total Number Research Articles

Capture of wild juveniles, growth and spawning of the southwestern Atlantic wreckfish (Polyprion americanus) in Argentina

Wreckfish (Polyprion americanus) is a marine fish of great interest as a new aquaculture species due to its easy adaptation to farming conditions, rapid growth and market price. In the Southwestern Atlantic Ocean, the species forms a genetic stock different from that of the Northern Hemisphere and also to populations of the South Pacific. This study presents the research conducted in Argentina from 2011 to 2020 on the development of a wreckfish broodstock from juvenile specimens. Wreckfish (n = 21) were caught with fishing rods at depth between 18 and 75 m depth, off the coast of Buenos Aires Province, Argentina (37°30′S - 39°00′S). All fish suffered barotrauma, but specimens captured at a depth < 45 m and whose swim bladders were deflated by puncture had a survival rate > 90%. Juvenile wreckfish (n = 12) with an initial body weight of 2–3 kg were kept in a recirculating aquaculture system (RAS) and fed local fish for 36 months. During this on-growing stage, a natural photoperiod regime with reduced light intensity was accompanied by seasonal variations in the RAS's thermal regime (14–19 °C). From then on, a maturity and reproductive protocol was implemented, where the temperature was lowered (12–17 °C) and the diet was complemented with a formulated semi-moist feed. Juvenile wreckfish grew fast, gaining about 2.5 kg in 11 months with a specific growth rate (SGRBW) of 0.2% day−1 and reaching 10–12 kg in 36 months. There was no significant difference in growth performance between sex groups during the on-growing stage. However, from months 36 to 57, the SGRBW of females (0.058 ± 0.008% day−1) was significantly higher than males (0.035 ± 0.005% day−1). After 67 months in captivity, the first natural spawning was achieved in a communal tank with a sex ratio 4 females: 6 males. Two consecutive spawning seasons were analysed, which showed a large daily variation in total number of eggs, percentage of floating eggs (potentially viable eggs) and spawning intervals. A marked improvement in spawning performance was observed from one season to the next. In the first season, a total production of 5.21 million eggs was reached, of which only about 2.7% were floating, while in the second season the values increased to 13.23 million eggs and 32.6%, respectively. We have successfully developed a broodstock of wreckfish capable of achieving natural spawning. Further research is needed to obtain reliable spawning and large production of high-quality eggs.

Evidence for stronger sexual selection in males than females using an adapted method of Bateman's classic study of Drosophila melanogaster.

Bateman's principles, originally a test of Darwin's theoretical ideas, has since become fundamental to sexual selection theory and vital to contextualising the role of anisogamy in sex differences of precopulatory sexual selection. Despite this, Bateman's principles have received substantial criticism, and researchers have highlighted both statistical and methodological errors, suggesting that Bateman's original experiment contains too much sampling bias for there to be any evidence of sexual selection. This study uses Bateman's original method as a template, accounting for two fundamental flaws in his original experiments, (i) viability effects and (ii) a lack of mating behaviour observation. Experimental populations of Drosophila melanogaster consisted of wild-type focal individuals and non-focal individuals established by backcrossing the brown eye (bw -) eye-colour marker - thereby avoiding viability effects. Mating assays included direct observation of mating behaviour and total number of offspring, to obtain measures of mating success, reproductive success, and standardised variance measures based on Bateman's principles. The results provide observational support for Bateman's principles, particularly that (i) males had significantly more variation in number of mates compared to females and (ii) males had significantly more individual variation in total number of offspring. We also find significantly steeper Bateman gradient for males compared to females, suggesting that sexual selection is operating more intensely in males. However, female remating was limited, providing the opportunity for future study to further explore female reproductive success in correlation with higher levels of remating.

Genotypic characterization of Staphylococcus chromogenes and Staphylococcus simulans from Swedish cases of bovine subclinical mastitis

Staphylococcus chromogenes and Staphylococcus simulans are commonly found in intramammary infections (IMI) associated with bovine subclinical mastitis, but little is known about genotypic variation and relatedness within species. This includes knowledge about genes encoding antimicrobial resistance (AMR) and potential virulence factors (pVF). The aim of this study was therefore to investigate these aspects by whole-genome sequencing of milk isolates from Swedish dairy cows with subclinical mastitis in an observational study. We also wanted to study if specific genotypes were associated with persistent IMI and the inflammatory response at udder quarter level. In total, 105 and 118 isolates of S. chromogenes and S. simulans, respectively, were included. Isolates were characterized using a 7-locus multilocus sequence typing (7-MLST), core genome analysis and in-silico analysis of AMR and pVF genes. Forty-seven sequence types (ST) and 7 core genome clusters of S. chromogenes were identified, and the most common ST were ST-6 and ST-109, both belonging to cluster VII. A 7-locus MLST scheme for S. simulans was not available, but 3 core genome clusters and 5 subclusters were described. Overall, substantial variation in ST and clusters among cows and herds were found in both species. Some ST of S. chromogenes were found in several herds, indicating spread between herds. Moreover, within-herd spread of the same genotype was observed for both species. Only a few AMR genes (blaZ, strpS194, vga(A)) were detected in a limited number of isolates, with the exception of blaZ coding for β-lactamase, which was identified in 22% of the isolates of S. chromogenes with ST-19, ST-102, and ST-103 more commonly carrying this gene compared with other STs. However, the blaZ gene was not identified in S. simulans. The average total number of pVF detected per isolate was similar in S. chromogenes (n = 30) and S. simulans (n = 33), but some variation in total numbers and presence of specific pVF or functional groups of pVF, was shown between ST/clusters within species. Differences in inflammatory response and potentially in persistent IMI at udder quarter level were found between S. chromogenes subtypes but not between S. simulans subtypes. In conclusion, the results from the present study generates new insight into the epidemiology of bovine S. chromogenes and S. simulans IMI, which can have implications for future prevention and antimicrobial treatment of infections related to these species.

The effect of Green lea aqueous extract Camellia sinensisand Vitamin E in infertile men in Tikrit city and It'sSuburbs

This study investigated the effects of Green tea aqueous extract and Vitamin I effect on the fertility of men, and the antioxidant and unti-infenile activity for comparison. The study included examination of (281) samples of seminal fluid of men thar were suffering from infertility caused by gonorrhea n :(144) , Varicose n: (47) , seminal vessels narrow 0: (31) , different inflammations n: (59) samples . and (60) samples from normal individuals (subjects) as a control, for the period from March(2008) 10 April(2009) in Tikrit city and its surrounding. The results appeared that adminstratio of green tea extract alone or with Vit. E in an infertile men (Gonorrhea infections, Varicocele |, Seminal vessels narrow and different sexual inflammations) lead to significant increase (p&lt;0.03) in total numbers , the average of movement and normal forms of sperm. The treatment with Vit. k alone lead to increase in numbers and normal forms of spermatozoa , however , no significant variations were of served in the average of movement. The results indicated that using green tes agueous exirct , VitE or both logether were effective to inducing significant increase in the concentrations of testosterone hormone. In noma) cases the results showed no significant variation in total numbers of sperms after with preen tea extract or ViLE adminstration. whereas acminstration both together showed a significant increase , also an increase in the average of movement and normal forms when patints treated with green tea extract alone or green extract incombination with VitFE bu no significant variations were observed when treated with Vit.E alone The results emphasized that using Vit. E or green tea extract or both together were effective in inducing a significant increase in the concentration of lestosicrone hormone The causes of the green lea extract effectivness relate 10 its consistence of antioxidants which reduced the free mdicals in the infertile men and caused an improvement of their fertility.

Recent Recovery of the World’s Rarest Primate Is Not Directly Linked to Increasing Habitat Quality

Due to habitat loss and hunting, the Hainan gibbon (Nomascus hainanus), the world’s rarest primate, was reduced to only two social groups and seven known individuals in 1978. Following the establishment of Bawangling National Natural Reserve (BNNR), gibbon forest habitat increased within this landscape from 56 km2 in 1980 to 300 km2, and the species had increased to five groups and 35 individuals by 2021. It is important to assess whether the large increase in habitat area was responsible for gibbon population increase, or whether gibbon recovery was associated with other factors. Here we use a 21-year longitudinal dataset of Hainan gibbon population change and habitat change, combined with vegetation survey plot data for 2021, to establish an accurate distribution baseline for natural tropical broadleaf forest across the BNNR landscape from 400 to 1300 m (the elevational range of gibbons at BNNR) and within the home range for each of the five Hainan gibbon social groups. We then utilized Landsat time-series images and analysis to compute non-linear causal relationships between forest dynamics and gibbon population growth from 2000 to 2021, both across BNNR and within each gibbon group home range. Metrics of forest dynamics include change in total forest area and forest fragmentation, and metrics of gibbon population dynamics include variation in total number of individuals for the entire population and within each social group, and variation in total number of groups. Our results demonstrate that overall gibbon population growth shows a positive relationship with improved habitat quality, with a one-year time lag of population response. However, changes in numbers of individuals within social groups do not show a similar relationship with improving habitat quality, suggesting that increasing forest cover and connectivity within the BNNR landscape are not direct determinants of Hainan gibbon recovery and that other environmental and/or anthropogenic factors are likely to be involved.

Triassic paleoclimate and paleofloristic trends of southwestern Gondwana (Argentina)

Earth's land plants have been shaped by tectonic, climatic and atmospheric evolution for at least 400 million years. The rift basins of Argentina record a continuous record of Triassic paleofloras through a wide paleolatitudinal range offer an opportunity to study the effect of paleoclimate on paleofloral changes through the Triassic period. We review previous work on southwestern Gondwana paleofloras of the Argentinean Triassic System and study the relationship between the palaeobotanical record and the inferred paleoclimatic conditions. The bibliographic review data were used to generate a presence/absence matrix. A cluster analysis, and a principal components analysis (PCA) were carried out to explore relationships among paleofloras. Also, variations in total number of genera per Triassic stage were plotted to elucidate biodiversity trends in the paleobotanical record. Finally, a canonical correspondence analysis (CCA) was performed in order to explore the relationship between the Triassic paleofloristic data and their interpreted paleoclimatic parameters, The influence of potential collection, taphonomic bias, and the uncertainties of the chronostrigraphic framework, on the integrity of the data are discussed. We conclude that the Early Triassic paleofloras developed under arid to semiarid with a marked concentration of seasonal precipitation during the summers; Middle Triassic under semi-arid to sub-humid with precipitation concentration during the summers; and Late Triassic paleofloras during early Carnian developed first under warm humid conditions without marked seasonality but by the Norian and Rhaetian conditions changed to semi-arid with winter rainfall.

Use Remote Sensing Techniques to Study Epiphytic Algae on Phragmites australis in Um El-Naaj Lake, Mysan Province, Southern Iraq

The aim of this study was to determine the quality and quantity composition of epiphytic algae of Phragmites australis in Um El-Naaj lake. Samples were collected from six Stations from November 2018 to October 2019.During this study, a remote sensing techniques was used to monitor the Community of epiphytic algae through storage and management data the geographic information system (GIS) program. The satellite images of the Landsat 8 satellite of the OLI which used to create visual images that facilitate the interpretation of the study area to identification and presence of these species and control their spread.The total number 306 species of epiphytic algae recorded during the study period were, belong to 61 genera. Seasonal variations in total number of species also noticed during the current study, Bacillariophyceae recorded 52.28%, with (160 species of 28 genera), Classes of Chlorophyceae and Cyanophycea recorded 12.67% (39 species of 20 genera 11) and 11.76% (36 species of 12 genera) respectively, while Classes of Fragilarphyceae recorded 14.37% ( 44species of 7genera), Coscinodisphyeceae recorded 13.59% (11 species, 7 genera). Then class of Euglenophyceae with 3.59%., Finally Chrysophyceae, Dinophyceae, and Rhodophyceae recorded 0.32% with 1 species of 1genera as they were present.

Does the Hygiene Hypothesis Explain COVID-19 Cases and Death? A Global Analysis

PurposeAt the start of the COVID-19 pandemic there was widespread speculation on the role of the hygiene hypothesis in the incidence and mortality of COVID-19. This study sought to determine if such a correlation exists via a global analysis using many surrogate factors representing the hygiene hypothesis.Methods & MaterialsPublicly available data from 190 countries were gathered. These data included COVID-19 total case numbers and deaths through December 28, 2020; water, sanitation, and hygiene (WaSH) metrics; data on mortality due to various types of air pollution; and other factors such as control of solid waste, emission growth rate of methane and carbon dioxide, and daily adjusted life years lost to unsafe drinking water and sanitation.Using IBM SPSS 27.0, these factors were analyzed using multiple regression analyses to determine the combination of factors most predictive of COVID-19 total cases and deaths. Separate regressions were conducted for the two criterion variables.ResultsThe analysis revealed positive correlations between two predictor variables: a nation's mortality due to air pollution (MDAP) and control of solid waste (CSW), with COVID-19 total number of cases. The combination of predictors accounted for approximately 28% of the variance in total number of cases. Concerning the number of COVID-19 deaths, 9.6% of the variance was accounted for by MDAP. Findings support previous studies pointing to the likelihood of air pollution as a potential catalyst for COVID-19 spread.ConclusionDecreasing air pollution is an important mitigating strategy for dealing with respiratory viruses, as it correlates with decreased damage to the respiratory system and decreased time for the virus to circulate in denser particles of polluted air. Thus, MDAP is an effective predictor of COVID-19 cases, and to a lesser extent, deaths. The positive correlation with cases and CSW indicates a likelihood that lockdowns throughout the world wreaked havoc on solid waste disposal systems, particularly in nations with prior effective CSW mechanisms. Although the hygiene hypothesis is not supported, findings should encourage societies to implement policies which focus on minimizing air pollution and strengthen systems to CSW and attenuate a descent into another global pandemic.

Pattern of Haematological Malignant Patients Attending OPD in a Tertiary Level Hospital in A Calendar Year

Background: Hematologic malignancies are of diverse incidence, prognosis, and etiology. Dhaka medical college hospital (DMCH) is a tertiary level hospital and dealing with patients attending from all over the country. We have analyzed data of patients present with hematological malignancy in our Out Patient Department (OPD). As Hematology Dept DMCH deal with patients referred from all over the country, its OPD data represents the picture of whole country. Methods: This is a retro-spective study of OPD patients with hematological malignancy in the department of Hematology of DMCH from January 2018 to December 2018. The diseases were diagnosed on the basis of bone marrow morphology or histopathology (Lymphoma) and or immunophenotyping &amp; molecular genetics. Results: Total 5747 patients were treated in 2018 with the complaints related to hematological malignancy of which 4599 (80%) were old patients and 1148 (20%) were new patients. Among all the treated patients 1420 (24.7%) were female and 4327 (75.3%) were male. Among 1148 new cases 37 were AL(3%), 386 were ALL (34%), 265 were AML(23%), 32 were CLL (3%), 126 were CML (11%), 40 were HL (3%), 18 were MDS (1%), 76 were MM (7%), 168 were NHL (15%). Data shows variation in total number of new patients per month- 83 in January (7.23%), 96 in February (8.36%), 140 in March (12.20%), 98 in April (8.54%), 94 in May (8.19), 89 in June (7.75%), 98 in July (8.54%), 66 in August (5.75%), 99 in September (8.62%), 103 in October (8.97%), 98 in November (8.54%), 84 in December (7.31%) But it does not show any statistical significant frequencies of diseases according to months. Conclusion: We deal a lot of patients with hematological malignancy each year in DMCH. A good portion of them are of ALL because of monthly maintenance of ALL protocols. Analysis of new cases shows ALL, AML, NHL is most common three diseases encounter in OPD. OPD patients’ inflow does not show any significant monthly variation for any of the diseases.

Skyrmions on 2D elastic surfaces with fixed boundary frame

We report simulation results of skyrmions on fluctuating 2D lattices, where the vertices ri(∈R3) are treated as a dynamical variable and, hence, there is no crystalline structure. On the fluctuating surfaces, an external magnetic field perpendicular to the surface, Dzyaloshinskii-Moriya and ferromagnetic interactions are assumed in addition to the Helfrich-Polyakov Hamiltonian for membranes. The surface (or frame) tension τ is calculated under both isotropic and uniaxial strain conditions, and this calculation clarifies a non-trivial dependence of τ on the skyrmion, stripe, and ferromagnetic phases. We find that the variation of τ with respect to the applied magnetic field in the skyrmion phase is accompanied by a variation of the total number of skyrmions. Moreover, we find that this total number variation is qualitatively consistent with a recent experimental result for the creation/annihilation of skyrmions of 3D crystalline material under uniaxial stress conditions. It is also found that the stripe phase is significantly influenced by uniaxial strains, while the skyrmion phase remains unchanged. These results allow us to conclude that the skyrmion phase is stable even on fluctuating surfaces.

Ecological and Environmental Management During the Hail 3D Transition-Zone Survey: Safe Working Practices Within a UNESCO World-Biosphere Reserve

Summary The Hail 3D transition-zone seismic survey, carried out by Abu Dhabi National Oil Company (ADNOC) in 2013–14, was located within an area considered to be of significant national and international environmental importance. Falling within a designated marine protected area (MPA) that was ratified by Abu Dhabi ministerial decree, as well as in a United Nations Educational, Scientific, and Cultural Organization (UNESCO) world-biosphere reserve, high standards of environmental and ecological management throughout the acquisition program were of paramount importance. Effective environmental and ecological management throughout the project was attained through the design and implementation of numerous working procedures and monitoring programs. These included the development of specific sets of mitigation guidelines for use during transition-zone surveys for minimizing disturbance and injury to marine mammals and turtles and for operating within mangrove areas, and the use of environmental profiling, auditing, and post-operational monitoring in both the terrestrial and marine environment for collecting new data on the biodiversity and ecology of the area. For the first time, we present ecological and environmental data collected over a period of 12 months within the Hail shoal area. In addition to data on species numbers and distributions, we present a method for effectively managing complex seismic surveys being carried out simultaneously in both the marine and terrestrial environment. For marine-mammal and turtle species, visual observations were compared over time and analyzed against seismic activity by use of a regression analysis. Our results demonstrate seasonal variation in total numbers throughout the year, with no significant reduction in observed numbers occurring as a result of seismic-exploration activities. We further demonstrate how a complex seismic survey can be managed and supervised to mitigate and minimize the environmental footprint or negative impacts on biodiversity as a result of the exploration and resource development considered crucial to the socioeconomic development of Abu Dhabi.

Lymph node ratio and surgical quality are strong prognostic factors of rectal cancer: results from a single referral centre.

Nodal stage is a strong prognostic factor of oncological outcome of rectal cancer. To compensate for the variation in total number of harvested nodes, calculation of the lymph node ratio (LNR) has been advocated. The aim of the study was to compare the impact, on the long-term oncological outcome, of the LNR with other predictive factors, including the quality of total mesorectal excision (TME) and the state of the circumferential resection margin. Consecutive patients having elective surgery for nonmetastatic rectal cancer were extracted from a prospectively maintained database. Retrospective uni- and multivariate analyses were performed based on patient-, surgical- and tumour-related factors. The prognostic value of the LNR on overall survival (OS) and on overall recurrence-free survival (ORFS) was assessed and a cut-off value was determined. From 1998 to 2013, out of 456 patients, 357 with nonmetastatic disease were operated on for rectal cancer. Neoadjuvant radiochemotherapy was administered to 66.7% of the patients. The mean number of lymph nodes retrieved was 12.8±8.78 per surgical specimen. A lower lymph node yield was obtained in patients who received neoadjuvant chemoradiotherapy (11.8 vs 14.2; P=0.014). The 5-year ORFS was 71.8% and the 5-year OS was 80.1%. Multivariate analysis confirmed LNR, the quality of TME and age to be independent prognostic factors of OS. LNR, age and perineural infiltration were independently associated with ORFS. Low- and high-risk patients could be discriminated using an LNR cut-off value of 0.2. LNR is an independent prognostic factor of OS and ORFS. In line with the principles of optimal surgical management, the quality of TME and lymph node yield are essential technical requirements.

Genetic variation in total number and locations of GnRH neurons identified using in situ hybridization in a wild-source population.

The evolution of brain function in the regulation of physiology may depend in part upon the numbers and locations of neurons. Wild populations of rodents contain natural genetic variation in the inhibition of reproduction by winter-like short photoperiod, and it has been hypothesized that this functional variation might be due in part to heritable variation in the numbers or location of gonadotropin releasing hormone (GnRH) neurons. A naturally variable wild-source population of white-footed mice was used to develop lines artificially selected for or against mature gonads in short, winter-like photoperiods. We compared a selection line that is reproductively inhibited in short photoperiod (Responsive) to a line that is weakly inhibited by short photoperiod (Nonresponsive) for differences in counts of neurons identified using in situ hybridization for GnRH mRNA. There was no effect of photoperiod, but there were 60% more GnRH neurons in total in the Nonresponsive selection line than the Responsive selection line. The lines differed specifically in numbers of GnRH neurons in more anterior regions, whereas numbers of GnRH neurons in posterior areas were not statistically different between lines. We compare these results to those of an earlier study that used immunohistochemical labeling for GnRH neurons. The results are consistent with the hypothesis that the selection lines and natural source population contain significant genetic variation in the number and location of GnRH neurons. The variation in GnRH neurons may contribute to functional variation in fertility that occurs in short photoperiods in the laboratory and in the wild source population in winter.

Model and scenario variations in predicted number of generations of Spodoptera litura Fab. on peanut during future climate change scenario.

The present study features the estimation of number of generations of tobacco caterpillar, Spodoptera litura. Fab. on peanut crop at six locations in India using MarkSim, which provides General Circulation Model (GCM) of future data on daily maximum (T.max), minimum (T.min) air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ensemble of the six from three emission scenarios (A2, A1B and B1). This data was used to predict the future pest scenarios following the growing degree days approach in four different climate periods viz., Baseline-1975, Near future (NF) -2020, Distant future (DF)-2050 and Very Distant future (VDF)—2080. It is predicted that more generations would occur during the three future climate periods with significant variation among scenarios and models. Among the seven models, 1–2 additional generations were predicted during DF and VDF due to higher future temperatures in CNRM-CM3, ECHams5 & CSIRO-Mk3.5 models. The temperature projections of these models indicated that the generation time would decrease by 18–22% over baseline. Analysis of variance (ANOVA) was used to partition the variation in the predicted number of generations and generation time of S. litura on peanut during crop season. Geographical location explained 34% of the total variation in number of generations, followed by time period (26%), model (1.74%) and scenario (0.74%). The remaining 14% of the variation was explained by interactions. Increased number of generations and reduction of generation time across the six peanut growing locations of India suggest that the incidence of S. litura may increase due to projected increase in temperatures in future climate change periods.

Delayed life history effects, multilevel selection, and evolutionary trade‐offs in the California tiger salamander

Delayed life history effects (DLHEs) occur when fitness in one life stage affects fitness in subsequent life stages. Given their biphasic life cycle, pond-breeding amphibians provide a natural system for studying DLHEs, although these effects are not restricted to species with biphasic life histories. In this study, we used multiple mark-recapture techniques enabled by a large trapping array to monitor components of fitness and resulting DLHEs in a population of the endangered California tiger salamander (Ambystoma californiense). We found that DLHEs are prominent across all life stage transitions and that there is variation in whether selection acts primarily at the individual or cohort level. We also demonstrated that there is more than an order of magnitude variation in mean cohort fitness, providing tremendous variation for DLHEs to act upon. We documented an evolutionary trade-off between mass at emergence and date of emergence, which may play a role in maintaining the variation in mass (fitness) at emergence. A literature review revealed that such high levels of intercohort variation occur in many other pond-breeding amphibians, and that appropriately documenting the magnitude of intercohort variation requires long-term studies (roughly two population turnovers). Given the profound effect that DLHEs can have on population dynamics, quantifying intercohort variation in mean fitness and the level(s) at which selection acts will be very important for developing accurate models of population dynamics. In general, when developing models of population dynamics, more attention should be paid to variation in mean fitness and not just variation in total numbers.

Synapsins I and II Are Not Required for Insulin Secretion from Mouse Pancreatic β-cells

Synapsins are a family of phosphoproteins that modulate the release of neurotransmitters from synaptic vesicles. The release of insulin from pancreatic β-cells has also been suggested to be regulated by synapsins. In this study, we have utilized a knock out mouse model with general disruptions of the synapsin I and II genes [synapsin double knockout (DKO)]. Stimulation with 20 mm glucose increased insulin secretion 9-fold in both wild-type (WT) and synapsin DKO islets, whereas secretion in the presence of 70 mm K(+) and 1 mm glucose was significantly enhanced in the synapsin DKO mice compared to WT. Exocytosis in single β-cells was investigated using patch clamp. The exocytotic response, measured by capacitance measurements and elicited by a depolarization protocol designed to visualize exocytosis of vesicles from the readily releasable pool and from the reserve pool, was of the same size in synapsin DKO and WT β-cells. The increase in membrane capacitance corresponding to readily releasable pool was approximately 50fF in both genotypes. We next investigated the voltage-dependent Ca(2+) influx. In both WT and synapsin DKO β-cells the Ca(2+) current peaked at 0 mV and measured peak current (I(p)) and net charge (Q) were of similar magnitude. Finally, ultrastructural data showed no variation in total number of granules (N(v)) or number of docked granules (N(s)) between the β-cells from synapsin DKO mice and WT control. We conclude that neither synapsin I nor synapsin II are directly involved in the regulation of glucose-stimulated insulin secretion and Ca(2)-dependent exocytosis in mouse pancreatic β-cells.

Spatio-temporal dynamics of bumblebee nest parasites (BombussubgenusPsythirusssp.) and their hosts (Bombusspp.)

1. A 39-year bumblebee data base was used to study the codistribution of six cuckoo bumblebees in the subgenus Psythirus of Bombus (hereafter called Psythirus) and their free-living bumblebee hosts in the British Isles. 2. A model of nest parasitism predicted host threshold densities and stable deterministic dynamics, with fluctuations only emerging as a result of environmental or demographic stochasticity. 3. Standardized transects indicated that variation in total number of records could be largely attributed to variation in observer effort; analyses were therefore carried out using relative abundance. 4. Spatially, parasite-free zones were evident in areas of low host abundance, but the host threshold for parasite presence differed among species and locations. 5. Temporally, the relative numbers of the parasite and host species remained relatively constant, except that the nest parasite P. campestris declined significantly since 1990. 6. There were consistent negative effects of the parasitic species on the numbers of hosts in the following year, and this pattern was seen over large geographic areas. 7. The spatio-temporal patterns confirmed a high degree of host specificity, except that P. campestris may be parasitizing not only B. pascuorum but also other species in the subgenus Thoracobombus.

Diversity and dominance of fungi inhabiting the sabkha area in Kuwait

We monitored the dominance and species diversity of fungi in hypersaline water bodies and saline depressions in Kuwait in the period February–October, 2007. There were considerable variations in total numbers and species diversity in concert with salinity variation. Among the most dominant isolates in high salinity water were several Cladosporium spp. and two moderately halophilic Acremonium spp. Several Alternaria -like strains were frequently found; they had various morphologies, but with identical ITS-5.8-ITS2 DNA sequences. Halophilic Cladosporium spp. and an undescribed Sporomiella sp. had best growth in 5% NaCl solutions.

Spatial structure of epiphytic yeast communities on fruits of Sorbus aucuparia L.

The subject of this research is epiphytic yeast communities that form on the surface of Sorbus aucuparia. The object is to make quantitative assessment of the yeast communities' differentiation of the same but distant substratum. Results of the factor variance nidicolous analysis demonstrated that with increase in distances, there are increases in the variation of total number and relative abundance of the dominant yeast communities. The average similarity between groups of single fruits (Sorensen's Quotient of Similarity) regularly decreased with distance. The results demonstrate that the number and structure of separate yeast groups depend not only on ecological factors but also on proximity to other communities. Such aggregation in the distribution of the microorganisms' species caused by migration and colonial resettlement should be taken into account when analyzing their diversity in natural habitats.

Regional variation in the utilization of carotid endarterectomy

In different regions of the United States, highly variable rates have been documented for a wide range of procedures, such as prostatectomy and caesarean section. It is generally held that this variation is due to inconsistent physician practice patterns or other nonmedical considerations. Only limited research has been conducted regarding vascular surgical operations. We examined national data on the utilization of carotid endarterectomy (CEA) to determine the extent and diversity of regional variations. Medicare discharge data quantified the per capita rate of CEA in 50 states and the District of Columbia in 2003. Multiple metrics pertaining to risk factors, socioeconomic status, access to care, provider density, and local health care capacity were quantified. We performed bivariate analysis, Pearson (PC) or Spearman (SC) correlations, and multiple regression modeling. In 2003, 83,164 CEAs were performed on 28,767,985 enrollees. CEA rates were 28.9 +/- 7.8 per 10,000 (range, 5.6-44.7 per 10,000). The rate of CEA was highly correlated with the number of heart disease deaths (PC = 0.575, P < .0001), deaths by stroke (PC = 0.504, P = .0002), and percentage of adult smokers in a state (PC = 0.643, P < .0001). These three factors held the strongest association with variation in CEA rates. Statistically, they explained 51% of the variation in total number of CEAs (R(2) = 0.5074, P < .0001). Median annual income (PC = -0.608, P < .0001) and percentage of college degrees (PC = -0.606, P < .0001) displayed inverse relationships to CEA rates. Per capita hospital beds (SC = 0.540, P < .0001) and rural health care clinics (SC = 0.518, P < .0001) exhibited positive correlations. The number of physicians or vascular surgeons did not predict higher utilization of CEA. The strongest correlations for CEA were three markers associated with atherosclerotic disease: percentage of adult smokers and deaths from heart disease or stroke. Geographic variation in this vascular procedure is chiefly associated with variance in markers of disease prevalence, not physician preference or other nonmedical factors. The increased utilization of carotid stenting, accompanied by the participation of a much wider range of medical specialists, may affect this relationship in the future.