63 research outputs found
Diversity and abundance of plankton in an artificial wetland, Tottino Ponds
Tottino Ponds is an artificial wetland created in the middle of agricultural fields, near Monterey Bay, and filled with recycled waste water. The site consists of four 25-meter square ponds. A study was conducted between October 2000 and April 2001 on the planktonic organisms living in the ponds. A series of one-liter samples were taken on four different dates. The samples were preserved and sorted. The samples contained a total of 121,526 organisms ranging in size from rotifers to a tadpole (Pseudacris). A measure of chlorophyll concentration was taken at the beginning and end of the study. The results showed that copepod, rotifer, and cladoceran abundance varied with time and remained constant from pond to pond. There was a negative correlation between cladoceran and chlorophyll abundance. The diversity of Tottino ponds throughout the survey, using Simpson\u27s diversity index (1-I), was 0.51
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Data report : trace element, Sr isotope, and Ge/SI composition of fluid and sediments in ridge-flank low-temperature hydrothermal environments
The data presented in this report demonstrate significant improvements
in the ability to constrain trace element and Sr isotopic
concentrations in sediments overlying ridge-flank hydrothermal
systems. Improved sampling methods orchestrated by the Integrated
Ocean Drilling Program (i.e., advanced piston coring and
anoxic sample processing) enabled the collection of reactive pore
water species with minimal alteration and sampling artifacts.
Improved methods of high-resolution inductively coupled
plasma–mass spectrometry trace element analysis, including the
use of the 8-hydroxyquinoline functional group to extract and
preconcentrate rare earth elements and other trace metals, were
used to compile a data set of 28 trace element concentrations and
⁸⁷Sr/⁸⁶Sr ratios. From this extensive data set, we were able to increase
the current understanding of how redox-reactive species respond
to diagenic processes. Near-basement trends were used in
combination with the known composition of hydrothermal fluids
that exit Baby Bare Springs to asses our ability to predict basement
fluid compositions using sediment pore water profiles collected
by deep-sea drilling. The results show that prediction of basement
fluid composition is possible for many trace elements, provided
the near-basement concentration gradients are minimal. In order
to place the Ge/Si systematics in a broader context, pore water
and borehole fluid Ge and Si data are presented from additional
sites across the Juan de Fuca Ridge flank and from two additional
ridge-flank settings. These data show that Ge concentrations and
Ge/Si ratios are much higher in the basement fluids than in the
basal sediments because of increased mobilization of Ge relative
to Si within the basement hydrothermal reservoir. Solid-phase
sediment data are presented, highlighted by the occurrence of
Mn- and carbonate-rich layers
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Homologous recombination repair intermediates promote efficient de novo telomere addition at DNA double-strand breaks
The healing of broken chromosomes by de novo telomere addition, while a normal developmental process in some organisms, has the potential to cause extensive loss of heterozygosity, genetic disease, or cell death. However, it is unclear how de novo telomere addition (dnTA) is regulated at DNA double-strand breaks (DSBs). Here, using a non-essential minichromosome in fission yeast, we identify roles for the HR factors Rqh1 helicase, in concert with Rad55, in suppressing dnTA at or near a DSB. We find the frequency of dnTA in rqh1Δ rad55Δ cells is reduced following loss of Exo1, Swi5 or Rad51. Strikingly, in the absence of the distal homologous chromosome arm dnTA is further increased, with nearly half of the breaks being healed in rqh1Δ rad55Δ or rqh1Δ exo1Δ cells. These findings provide new insights into the genetic context of highly efficient dnTA within HR intermediates, and how such events are normally suppressed to maintain genome stabilit
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Proprioceptive Coupling within Motor Neurons Drives C. Elegans Forward Locomotion
Locomotion requires coordinated motor activity throughout an animal’s body. In both vertebrates and invertebrates, chains of coupled central pattern generators (CPGs) are commonly evoked to explain local rhythmic behaviors. In C. elegans, we report that proprioception within the motor circuit is responsible for propagating and coordinating rhythmic undulatory waves from head to tail during forward movement. Proprioceptive coupling between adjacent body regions transduces rhythmic movement initiated near the head into bending waves driven along the body by a chain of reflexes. Using optogenetics and calcium imaging to manipulate and monitor motor circuit activity of moving C. elegans held in microfluidic devices, we found that the B-type cholinergic motor neurons transduce the proprioceptive signal. In C. elegans, a sensorimotor feedback loop operating within a specific type of motor neuron both drives and organizes body movement.Chemistry and Chemical BiologyPhysic
Trends in weight gain recorded in English primary care before and during the Coronavirus-19 pandemic: An observational cohort study using the OpenSAFELY platform.
BACKGROUND: Obesity and rapid weight gain are established risk factors for noncommunicable diseases and have emerged as independent risk factors for severe disease following Coronavirus Disease 2019 (COVID-19) infection. Restrictions imposed to reduce COVID-19 transmission resulted in profound societal changes that impacted many health behaviours, including physical activity and nutrition, associated with rate of weight gain. We investigated which clinical and sociodemographic characteristics were associated with rapid weight gain and the greatest acceleration in rate of weight gain during the pandemic among adults registered with an English National Health Service (NHS) general practitioner (GP) during the COVID-19 pandemic. METHODS AND FINDINGS: With the approval of NHS England, we used the OpenSAFELY platform inside TPP to conduct an observational cohort study of routinely collected electronic healthcare records. We investigated changes in body mass index (BMI) values recorded in English primary care between March 2015 and March 2022. We extracted data on 17,742,365 adults aged 18 to 90 years old (50.1% female, 76.1% white British) registered with an English primary care practice. We estimated individual rates of weight gain before (δ-prepandemic) and during (δ-pandemic) the pandemic and identified individuals with rapid weight gain (>0.5 kg/m2/year) in each period. We also estimated the change in rate of weight gain between the prepandemic and pandemic period (δ-change = δ-pandemic-δ-prepandemic) and defined extreme accelerators as the 10% of individuals with the greatest increase in their rate of weight gain (δ-change ≥1.84 kg/m2/year) between these periods. We estimated associations with these outcomes using multivariable logistic regression adjusted for age, sex, index of multiple deprivation (IMD), and ethnicity. P-values were generated in regression models. The median BMI of our study population was 27.8 kg/m2, interquartile range (IQR) [24.3, 32.1] in 2019 (March 2019 to February 2020) and 28.0 kg/m2, IQR [24.4, 32.6] in 2021. Rapid pandemic weight gain was associated with sex, age, and IMD. Male sex (male versus female: adjusted odds ratio (aOR) 0.76, 95% confidence interval (95% CI) [0.76, 0.76], p < 0.001), older age (e.g., 50 to 59 years versus 18 to 29 years: aOR 0.60, 95% CI [0.60, 0.61], p < 0.001]); and living in less deprived areas (least-deprived-IMD-quintile versus most-deprived: aOR 0.77, 95% CI [0.77, 0.78] p < 0.001) reduced the odds of rapid weight gain. Compared to white British individuals, all other ethnicities had lower odds of rapid pandemic weight gain (e.g., Indian versus white British: aOR 0.69, 95% CI [0.68, 0.70], p < 0.001). Long-term conditions (LTCs) increased the odds, with mental health conditions having the greatest effect (e.g., depression (aOR 1.18, 95% CI [1.17, 1.18], p < 0.001)). Similar characteristics increased odds of extreme acceleration in the rate of weight gain between the prepandemic and pandemic periods. However, changes in healthcare activity during the pandemic may have introduced new bias to the data. CONCLUSIONS: We found female sex, younger age, deprivation, white British ethnicity, and mental health conditions were associated with rapid pandemic weight gain and extreme acceleration in rate of weight gain between the prepandemic and pandemic periods. Our findings highlight the need to incorporate sociodemographic, physical, and mental health characteristics when formulating research, policies, and interventions targeting BMI in the period of post pandemic service restoration and in future pandemic planning
Experiences of people seen in an acute hospital setting by a liaison mental health service: responses from an online survey
Background-
In recent years the UK has expanded the provision of liaison mental health services (LMHS). Little work has been undertaken to explore first-hand experiences of them.
Aims-
The aim of this study was to gain insights into the experiences of users of LMHS in both emergency departments and acute inpatient wards in the UK.
Methods-
This cross-sectional internet survey was initially advertised from May-July 2017 using the social media platform Facebook. Due to a paucity of male respondents, it was re-run from November 2017-February 2018, specifically targeting male respondents. The survey featured a structured questionnaire divided into three categories: the profile of the respondent, perceived professionalism of LMHS and overall opinion of the service.
Analysis-
Responses to the structured questionnaire were analysed using descriptive statistics and latent class analysis. Free-text responses were transcribed verbatim and interpreted using thematic analysis.
Results-
184 people responded to the survey. 147 were service users and 37 were partners, friends or family members of service users. Only 31% of service users and 27% of close others found their overall contact helpful. Latent class analysis identified three clusters − 46% of service users generally disliked their contact, 36% had an overall positive experience, and 18% did not answer most questions about helpfulness or usefulness. Features most frequently identified as important were the provision of a 24/7 service, assessment by a variety of healthcare professionals and national standardisation of services. Respondents indicated that the least important feature was the provision of a separate service for older people. They desired faster assessments following referral from the parent team, clearer communication about next steps and greater knowledge of local services and third sector organisations.
Conclusions-
This survey identified mixed responses, but overall experiences were more negative than indicated in the limited previous research. The evaluation and adaptation of LMHS along the lines suggested in our survey should be prioritised to enhance their inherent therapeutic value and to improve engagement with treatment and future psychiatric care
A distinct and active bacterial community in cold oxygenated fluids circulating beneath the western flank of the Mid-Atlantic ridge
The rock-hosted, oceanic crustal aquifer is one of the largest ecosystems on Earth, yet little is known about its indigenous microorganisms. Here we provide the first phylogenetic and functional description of an active microbial community residing in the cold oxic crustal aquifer. Using subseafloor observatories, we recovered crustal fluids and found that the geochemical composition is similar to bottom seawater, as are cell abundances. However, based on relative abundances and functional potential of key bacterial groups, the crustal fluid microbial community is heterogeneous and markedly distinct from seawater. Potential rates of autotrophy and heterotrophy in the crust exceeded those of seawater, especially at elevated temperatures (25 °C) and deeper in the crust. Together, these results reveal an active, distinct, and diverse bacterial community engaged in both heterotrophy and autotrophy in the oxygenated crustal aquifer, providing key insight into the role of microbial communities in the ubiquitous cold dark subseafloor biosphere
Rapid Identification of Novel Psychoactive and Other Controlled Substances Using Low-Field 1H NMR Spectroscopy
An automated approach to the collection of 1H NMR (nuclear magnetic resonance) spectra using a benchtop NMR spectrometer and the subsequent analysis, processing, and elucidation of components present in seized drug samples are reported. An algorithm is developed to compare spectral data to a reference library of over 300 1H NMR spectra, ranking matches by a correlation-based score. A threshold for identification was set at 0.838, below which identification of the component present was deemed unreliable. Using this system, 432 samples were surveyed and validated against contemporaneously acquired GC–MS (gas chromatography–mass spectrometry) data. Following removal of samples which possessed no peaks in the GC–MS trace or in both the 1H NMR spectrum and GC–MS trace, the remaining 416 samples matched in 93% of cases. Thirteen of these samples were binary mixtures. A partial match (one component not identified) was obtained for 6% of samples surveyed whilst only 1% of samples did not match at all
The Core Apoptotic Executioner Proteins CED-3 and CED-4 Promote Initiation of Neuronal Regeneration in Caenorhabditis elegans
Laser severing of individual axons in the nematode Caenorhabditis elegans revealed that the apoptotic executioner caspase CED-3 and its regulator CED-4/Apaf-1 play an unexpected beneficial role in promoting axonal regeneration
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