313 research outputs found
Effects of husbandry parameters on the life-history traits of the apple snail, Marisa cornuarietis: effects of temperature, photoperiod, and population density
These experiments are part of a larger study designed to investigate the influence of husbandry parameters on the life history of the apple snail, Marisa cornuarietis. The overall objective of the program is to identify suitable husbandry conditions for maintaining multi-generation populations of this species in the laboratory for use in ecotoxicological testing. In this article, we focus on the effects of photoperiod, temperature, and population density on adult fecundity and juvenile growth. Increasing photoperiod from 12 to 16 h of light per day had no effect on adult fecundity or egg hatching and relatively minor effects on juvenile growth and development. Rearing snails at temperatures between 22°C and 28°C did not influence the rates of egg production or egg clutch size. However, the rates of growth and development (of eggs and juveniles) increased with increasing temperature in this range, and when temperatures were reduced to 22°C egg-hatching success was impaired. Juvenile growth and development were more sensitive to rearing density than adult fecundity traits. On the basis of the present results, we conclude that rearing individuals of M. cornuarietis at a temperature of 25°C, a photoperiod of 12L:12D, and a density of <0.8 snails Lâ1 (with lower densities for juvenile snails) should provide favorable husbandry conditions for maintaining multi-generation populations of this species
Evolution of the Freshwater Sardinella, Sardinella Tawilis (Clupeiformes: Clupeidae), in Taal Lake, Philippines and Identification of iIts Marine Sister-Species, Sardinella Hualiensis
We identify the sister species of the world\u27s only freshwater sardinella, Sardinella tawilis (Herre, 1927) of Taal Lake, Philippines as the morphologically-similar marine Taiwanese sardinella Sardinella hualiensis (Chu and Tsai, 1958). Evidence of incomplete lineage sorting and a species tree derived from three mitochondrial genes and one nuclear gene indicate that S. tawilis diverged from S. hualiensis in the late Pleistocene. Neutrality tests, mismatch distribution analysis, sequence diversity indices, and species tree analysis indicate populations of both species have long been stable and that the divergence between these two lineages occurred prior to the putative 18th century formation of Taal Lake
A systemic BIM innovation model in the construction supply chain
BIM innovation research has mainly focused on diffusion models of acceptance at the individual and organisational levels. However, BIM has the potential to bring together multiple organisations working collaboratively in a coordinated fashion. Realising this potential requires a study of BIM innovation at the inter-organisational level, which is considered to be systemic BIM innovation. Systemic BIM innovation and its effect in the
construction supply chain have not been sufficiently investigated. The aim of this paper is to present a critical review of literature on the diffusion of BIM innovation in the construction industry. A conceptual model of systemic BIM innovation is developed and presented. The proposed model incorporates factors such as individual BIM acceptance, organisation's drivers of BIM usage, organisation's linkages, supply chain management challenges, and the role of context. It is found that variables facilitating systemic BIM innovation are interrelated at different analytical levels, and are shaped by the context. Directions for future research and empirical validation are presented
Reflecting on loss in Papua New Guinea
This article takes up the conundrum of conducting anthropological fieldwork with people who claim that they have 'lost their culture,' as is the case with Suau people in the Massim region of Papua New Guinea. But rather than claiming culture loss as a process of dispossession, Suau claim it as a consequence of their own attempts to engage with colonial interests. Suau appear to have responded to missionization and their close proximity to the colonial-era capital by jettisoning many of the practices characteristic of Massim societies, now identified as 'kastom.' The rejection of kastom in order to facilitate their relations with Europeans during colonialism, followed by the mourning for kastom after independence, both invite consideration of a kind of reflexivity that requires action based on the presumed perspective of another
Hidden Diversity in Sardines: Genetic and Morphological Evidence for Cryptic Species in the Goldstripe Sardinella, Sardinella gibbosa (Bleeker, 1849)
Cryptic species continue to be uncovered in many fish taxa, posing challenges for fisheries conservation and management. In Sardinella gibbosa, previous investigations revealed subtle intra-species variations, resulting in numerous synonyms and a controversial taxonomy for this sardine. Here, we tested for cryptic diversity within S. gibbosa using genetic data from two mitochondrial and one nuclear gene regions of 248 individuals of S. gibbosa, collected from eight locations across the Philippine archipelago. Deep genetic divergence and subsequent clustering was consistent across both mitochondrial and nuclear markers. Clade distribution is geographically limited: Clade 1 is widely distributed in the central Philippines, while Clade 2 is limited to the northernmost sampling site. In addition, morphometric analyses revealed a unique head shape that characterized each genetic clade. Hence, both genetic and morphological evidence strongly suggests a hidden diversity within this common and commercially-important sardine
How effective are the non-conventional ovarian stimulation protocols in ART? A systematic review and meta-analysis
Purpose: To compare the effectiveness of starting the ovarian stimulation on the early follicular phase (âConventionalâ) with the newer range of non-conventional approaches starting in the luteal phase (âLutealâ), random-start, and studies implementing them in DuoStim (âConventionalâ+âLutealâ). Methods: Systematic review. We searched CENTRAL, PubMed, and Embase, on March 2020. We included randomized and non-randomized controlled trials that compared âLuteal,â random-start ovarian stimulation or DuoStim with âConventionalâ; we analyzed them by subgroups: oocyte freezing and patients undergoing ART treatments, both, in the general infertile population and among poor responders. Results: The following results come from a sensitivity analysis that included only the low/moderate risk of bias studies. When comparing âLutealâ to âConventional,â clinically relevant differences in MII oocytes were ruled out in all subgroups. We found that âLutealâ probably increases the COH length both, in the general infertile population (OR 2.00Â days, 95% CI 0.81 to 3.19, moderate-quality evidence) and in oocyte freezing cycles (MD 0.85Â days, 95% CI 0.53 to 1.18, moderate-quality evidence). When analyzing DuoStim among poor responders, we found that it appears to generate a higher number of MII oocytes in comparison with a single âConventionalâ (MD 3.35, 95%CI 2.54â4.15, moderate-quality evidence). Conclusion: Overall, this systematic review of the available data demonstrates that in poor responders, general infertile population and oocyte freezing for cancer stimulation in the late follicular and luteal phases can be utilized in non-conventional approaches such as random-start and DuoStim cycles, offering similar outcomes to the conventional cycles but potentially with increased flexibility, within a reduced time frame. However, more well-designed trials are required to establish certainty.Fil: Glujovsky, Demian. Centro de Estudios en GinecologĂa y ReproducciĂłn; Argentina. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Pesce, Romina. Hospital Italiano; ArgentinaFil: Miguens, Mariana. Centro de Estudios en GinecologĂa y ReproducciĂłn; ArgentinaFil: Sueldo, Carlos E.. Centro de Estudios en GinecologĂa y ReproducciĂłn; Argentina. University Of California, San Francisco; Estados UnidosFil: Lattes, Karinna. No especifĂca;Fil: Ciapponi, AgustĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica. Instituto de Efectividad ClĂnica y Sanitaria. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica; Argentin
Temporal decorrelation of collective oscillations in neural networks with local inhibition and long-range excitation
We consider two neuronal networks coupled by long-range excitatory
interactions. Oscillations in the gamma frequency band are generated within
each network by local inhibition. When long-range excitation is weak, these
oscillations phase-lock with a phase-shift dependent on the strength of local
inhibition. Increasing the strength of long-range excitation induces a
transition to chaos via period-doubling or quasi-periodic scenarios. In the
chaotic regime oscillatory activity undergoes fast temporal decorrelation. The
generality of these dynamical properties is assessed in firing-rate models as
well as in large networks of conductance-based neurons.Comment: 4 pages, 5 figures. accepted for publication in Physical Review
Letter
Quality of evidence matters: is it well reported and interpreted in infertility journals?
Purpose: To evaluate if the authors of published systematic reviews (SRs) reported the level of quality of evidence (QoE) in the top 5 impact factor infertility journals and to analyze if they used an appropriate wording to describe it. Methods: This is a cross-sectional study. We searched in PubMed for SRs published in 2017 in the five infertility journals with the highest impact factor. We analyzed the proportion of SRs published in the top 5 impact factor infertility journals that reported the SRsâ QoE, and the proportion of those SRs in which authors used consistent wording to describe QoE and magnitude of effect. Results: The QoE was reported in only 21.4% of the 42 included SRs and in less than 10% of the abstracts. Although we did not find important differences in the report of QoE of those that showed statistically significant differences or not, p value was associated with the wording chosen by the authors. We found inconsistent reporting of the size the effect estimate in 54.8% (23/42) and in the level of QoE in 92.9% (39/42). Whereas the effect size was more consistently expressed in studies with statistically significant findings, QoE was better expressed in those cases in which the p value was over 0.05. Conclusion: We found that in 2017, less than 25% of the authors reported the overall QoE when publishing SRs. Authors focused more on statistical significance as a binary concept than on methodological limitations like study design, imprecision, indirectness, inconsistency, and publication bias. Authors should make efforts to report the QoE and interpret results accordingly.Fil: Glujovsky, Demian. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Sueldo, Carlos E.. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Bardach, Ariel Esteban. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica. Instituto de Efectividad ClĂnica y Sanitaria. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica; Argentina. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: del Pilar Valanzasca, MarĂa. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: ComandĂ©, Daniel. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Ciapponi, AgustĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica. Instituto de Efectividad ClĂnica y Sanitaria. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica; Argentina. Instituto de Efectividad ClĂnica y Sanitaria; Argentin
Functional evolution of quantum cylindrical waves
Kucha{\v{r}} showed that the quantum dynamics of (1 polarization) cylindrical
wave solutions to vacuum general relativity is determined by that of a free
axially-symmetric scalar field along arbitrary axially-symmetric foliations of
a fixed flat 2+1 dimensional spacetime. We investigate if such a dynamics can
be defined {\em unitarily} within the standard Fock space quantization of the
scalar field.
Evolution between two arbitrary slices of an arbitrary foliation of the flat
spacetime can be built out of a restricted class of evolutions (and their
inverses). The restricted evolution is from an initial flat slice to an
arbitrary (in general, curved) slice of the flat spacetime and can be
decomposed into (i) `time' evolution in which the spatial Minkowskian
coordinates serve as spatial coordinates on the initial and the final slice,
followed by (ii) the action of a spatial diffeomorphism of the final slice on
the data obtained from (i). We show that although the functional evolution of
(i) is unitarily implemented in the quantum theory, generic spatial
diffeomorphisms of (ii) are not. Our results imply that a Tomanaga-Schwinger
type functional evolution of quantum cylindrical waves is not a viable concept
even though, remarkably, the more limited notion of functional evolution in
Kucha{\v{r}}'s `half parametrized formalism' is well-defined.Comment: Replaced with published versio
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