100 research outputs found
Extirpation of N otropis simus simus (Cope) and N otropis orca Woolman (Pisces: Cyprinidae) from the Rio Grande in New Mexico, with Notes on Their Life History
The Rio Grande bluntnose shiner, Notropis simus simus, and the phantom shiner, Notropis orca, once occupied warm water reaches of the Rio Grande in New Mexico, but have not been collected there since 1964 and 1949, respectively. Notropis s. simus was widespread and common until 1950; N. orca was apparently never abundant. Our collections indicated that both forms are extirpated from New Mexico, and each may be extinct. Two other cyprinids, Rio Grande shiner, Notropis jemezanus, and speckled chub, Hybopsis aestivalis, also disappeared from the Rio Grande around 1949 and 1964, respectively. A fifth cyprinid, the Rio Grande silvery minnow, Hybognathus amarus, is presently reduced in distribution and abundance. Irrigation withdrawals and mainstream dams altered natural discharge patterns of the Rio Grande prior to 1930 and probably reduced populations of this suite of mainstream fishes. Drought and increased water withdrawal after 1950 periodically dried extensive reaches of warm water Rio Grande habitat and probably eliminated remaining small populations of the aforementioned species except H. amarus. Life history attributes of N. s. simus, and the distribution and habitat of all of the other extirpated forms do not indicate special requirements other than a flowing mainstream environment. Short-lived fishes that occupy exclusively mainstream riverine environments are especially susceptible to extirpation when flow regimes are altered
Thermodynamics of pairing in mesoscopic systems
Using numerical and analytical methods implemented for different models we
conduct a systematic study of thermodynamic properties of pairing correlation
in mesoscopic nuclear systems. Various quantities are calculated and analyzed
using the exact solution of pairing. An in-depth comparison of canonical, grand
canonical, and microcanonical ensemble is conducted. The nature of the pairing
phase transition in a small system is of a particular interest. We discuss the
onset of discontinuity in the thermodynamic variables, fluctuations, and
evolution of zeros of the canonical and grand canonical partition functions in
the complex plane. The behavior of the Invariant Correlational Entropy is also
studied in the transitional region of interest. The change in the character of
the phase transition due to the presence of magnetic field is discussed along
with studies of superconducting thermodynamics.Comment: 19 pages, 24 figure
Winter wheat, 2000
"July 2000.""Publication costs paid by Missouri Seed Improvement Association."The objective of the Missouri Winter Wheat Performance Tests is to provide wheat growers in Missouri with a reliable, unbiased, up-to-date source of information that will permit valid comparisons among improved wheat varieties. This information should help Missouri wheat growers select varieties best suited to their particular area and growing conditions. This report summarizes soft red winter wheat variety trials conducted throughout Missouri during the 1999-00 cropping season. No hard red winter wheat test was grown in 2000
Synthesis, structures and magnetic properties of [(η9-C9H9)Ln(η8-C8H8)] super sandwich complexes
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Colonization and extinction in dynamic habitats: an occupancy approach for a Great Plains stream fish assemblage
Despite the importance of habitat in determining species distribution and persistence, habitat dynamics are rarely modeled in studies of metapopulations. We used an integrated habitat-occupancy model to simultaneously quantify habitat change, site fidelity, and local colonization and extinction rates for larvae of a suite of Great Plains stream fishes in the Arikaree River, eastern Colorado, USA, across three years. Sites were located along a gradient of flow intermittency and groundwater connectivity. Hydrology varied across years: the first and third being relatively wet and the second dry. Despite hydrologic variation, our results indicated that site suitability was random from one year to the next. Occupancy probabilities were also independent of previous habitat and occupancy state for most species, indicating little site fidelity. Climate and groundwater connectivity were important drivers of local extinction and colonization, but the importance of groundwater differed between periods. Across species, site extinction probabilities were highest during the transition from wet to dry conditions (range: 0.52-0.98), and the effect of groundwater was apparent with higher extinction probabilities for sites not fed by groundwater. Colonization probabilities during this period were relatively low for both previously dry sites (range: 0.02-0.38) and previously wet sites (range: 0.02-0.43). In contrast, no sites dried or remained dry during the transition from dry to wet conditions, yielding lower but still substantial extinction probabilities (range: 0.16-0.63) and higher colonization probabilities (range: 0.06-0.86), with little difference among sites with and without groundwater. This approach of jointly modeling both habitat change and species occupancy will likely be useful to incorporate effects of dynamic habitat on metapopulation processes and to better inform appropriate conservation actions.KEYWORDS: Stream fishes, Species occurrence, Great Plains, USA, Intermittent streams, Groundwater, Joint habitat occupancy modeling, Metapopulation
Classification of the Nuclear Multifragmentation Phase Transition
Using a recently proposed classification scheme for phase transitions in
finite systems [Phys.Rev.Lett.{\bf 84},3511 (2000)] we show that within the
statistical standard model of nuclear multifragmentation the predicted phase
transition is of first order.Comment: 5 pages, 4 eps figures, accepted for publication in Phys.Rev.C (in
press
Does training increase the use of more emotionally laden words by nurses when talking with cancer patients? A randomised study
The emotional content of health care professionals–cancer patient communication is often considered as poor and has to be improved by an enhancement of health care professionals empathy. One hundred and fifteen oncology nurses participating in a communication skills training workshop were assessed at three different periods. Nurses randomly allocated to a control group arm (waiting list) were assessed a first time and then 3 and 6 months later. Nurses allocated to the training group were assessed before training workshop, just after and 3 months later. Each nurse completed a 20-min clinical and simulated interview. Each interview was analysed by three content analysis systems: two computer-supported content analysis of emotional words, the Harvard Third Psychosocial Dictionary and the Martindale Regressive Imagery Dictionary and an observer rating system of utterances emotional depth level, the Cancer Research Campaign Workshop Evaluation Manual. The results show that in clinical interviews there is an increased use of emotional words by health care professionals right after having been trained (P=0.056): training group subjects use 4.3 (std: 3.7) emotional words per 1000 used before training workshop, and 7.0 (std: 5.8) right after training workshop and 5.9 (std: 4.3) 3 months later compared to control group subjects which use 4.5 (std: 4.8) emotional words at the first assessment point, 4.3 (std: 4.1) at the second and 4.4 (std: 3.3) at the third. The same trend is noticeable for emotional words used by health care professionals in simulated interviews (P=0.000). The emotional words registry used by health care professionals however remains stable over time in clinical interviews (P=0.141) and is enlarged in simulated interviews (P=0.041). This increased use of emotional words by trained health care professionals facilitates cancer patient emotion words expressions compared to untrained health care professionals especially 3 months after training (P=0.005). This study shows that health care professionals empathy may be improved by communication skills training workshop and that this improvement facilitates cancer patients emotions expression
Age-Specific Estimates Indicate Potential Deleterious Capture Effects and Low Survival of Stocked Juvenile Colorado Pikeminnow (\u3ci\u3ePtychocheilus lucius\u3c/i\u3e)
Hatcheries and stocking programs have become necessary to repatriate or augment populations of imperiled fishes worldwide. Over nearly two decades, millions of endangered juvenile Colorado Pikeminnow Ptychocheilus lucius have been stocked into the San Juan River (Colorado, New Mexico, and Utah); however, recruitment of these individuals to adult life stages (age ≥6) remains low. Using a mark–recapture data set collected from annual riverwide electrofishing efforts between 2003 and 2016, we investigated apparent survival and capture probabilities of stocked Colorado Pikeminnow to identify age‐specific bottlenecks contributing to this lack of recruitment. With relatively high capture rates, which averaged between 0.34 and 0.39 for the first 2 years after an individual\u27s first encounter, our results indicated that survival was consistently less than 0.25 for young age‐groups (i.e., ages 1–3), and no appreciable increase in survival occurred until fish had been in the river for at least 3 years (i.e., age ≥4+). Although age and capture effects were confounded for most age‐groups, capture appeared to reduce apparent survival for age‐2 fish by approximately 50%. The confounding effects of age, a completely hatchery‐origin population, and extensive environmental alterations to the San Juan River make it difficult to disentangle factors associated with this overall reduced juvenile survival
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Headwater Streams and Wetlands are Critical for Sustaining Fish, Fisheries, and Ecosystem Services
Headwater streams and wetlands are integral components of watersheds that are critical for biodiversity, fisheries, ecosystem functions, natural resource-based economies, and human society and culture. These and other ecosystem services provided by intact and clean headwater streams and wetlands are critical for a sustainable future. Loss of legal protections for these vulnerable ecosystems would create a cascade of consequences, including reduced water quality, impaired ecosystem functioning, and loss of fish habitat for commercial and recreational fish species. Many fish species currently listed as threatened or endangered would face increased risks, and other taxa would become more vulnerable. In most regions of the USA, increased pollution and other impacts to headwaters would have negative economic consequences. Headwaters and the fishes they sustain have major cultural importance for many segments of U.S. society. Native peoples, in particular, have intimate relationships with fish and the streams that support them. Headwaters ecosystems and the natural, socio-cultural, and economic services they provide are already severely threatened, and would face even more loss under the Waters of the United States (WOTUS) rule recently proposed by the Trump administration
An engineering perspective of vacuum assisted delivery devices in obstetrics: A review
Complications during childbirth result in the need for clinicians to use ‘assisted delivery’ in over 12% of cases (UK). After more than 50 years in clinical practice, vacuum assisted delivery (VAD) devices remain a mainstay in physically assisting child delivery; sometimes preferred over forceps due to their ease of use and reduced maternal morbidity. Despite their popularity and enduring track-record, VAD devices have shown little evidence of innovation or design change since their inception. In addition, evidence on the safety and functionality of VAD devices remains limited but does present opportunities for improvements to reduce adverse clinical outcomes. Consequently in this review we examine the literature and patent landscape surrounding VAD biomechanics, design evolution and performance from an engineering perspective, aiming to collate the limited but valuable information from a disparate field and provide a series of recommendations to inform future research into improved, safer, VAD systems
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