2,070 research outputs found
Food insecurity and childhood obesity: beyond categorical and linear representations
Previous work on the relationship between food insecurity and childhood overweight has lead to a wide array of answers – some have found a positive relationship, others no relationship, and still others a negative relationship. This previous work has shared one thing in common – all have used parametric models. In this paper we move beyond parametric models by using non-parametric models. With data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES) and a wide array parametric methods, we find evidence across different samples of a positive relationship, no relationship, and a negative relationship between childhood overweight and food insecurity. When we turn to non-parametric methods, however, this ambiguity across samples is not as prevalent. Instead, across different samples, we find (a) increases in the probability of food insecurity in the middle of the BMI distribution, (b) increases in the probability at the very high end of the BMI, and (c) no relationship across the entire distribution. We present some parametric models that roughly mimic these relationships. Our results indicate that efforts to reduce food insecurity will either have no impact on childhood overweight or would lead to reductions in childhood overweight.Food Consumption/Nutrition/Food Safety, Food Security and Poverty,
Effect of Hippocampal CREB Deletion on Models of Anxiety, Depression, and Antidepressant Response
Depression is the most common psychiatric disorder, yet current antidepressants are inadequate as they require weeks of treatment to alleviate symptoms. The mechanism by which the immediate effects of antidepressants cause later behavioral improvements remains unknown, focusing research on downstream signaling events triggered by antidepressant administration. Expression and activity of the transcription factor CREB are increased by antidepressant drugs, and CREB targets include genes known to be involved in antidepressant response. However, the effects of manipulating CREB depend on the brain region examined, with initial studies showing an antidepressant role for CREB in the hippocampus. To investigate the hippocampal-specific importance of CREB in depression-related behaviors and response to antidepressant drugs, we used CrebloxP/loxP mice, in which CREB deletion could be induced by injection of an adeno-associated virus expressing Cre recombinase. Robust and specific deletion of CREB protein throughout the hippocampus was achieved via viral injection to this region in adult mice. Acute response to antidepressants in the forced swim test, a common behavioral assay for antidepressant efficacy, was unaffected by hippocampal CREB deletion. In an assay sensitive to chronic antidepressant response, the novelty-induced hypophagia (NIH) paradigm, hippocampal CREB deletion did not alter response to chronic antidepressant treatment. However, mice with hippocampal deletion of CREB also responded to acute antidepressant treatment in the NIH, an accelerated response to antidepressants, as control mice responded only to chronic, but not acute, treatment in this paradigm. Additionally, loss of CREB from the hippocampus increased hippocampal neurogenesis, which may be related to the accelerated response to antidepressants in the NIH in these mice. These results mimic the phenotype of a constitutive knockout of CREB, suggesting that the phenotype does not result from developmental loss of CREB. The CREB-family protein CREM was upregulated following deletion of CREB, demonstrating that regulation within this family is highly dynamic. CREM may functionally compensate for the lack of CREB by maintaining or increasing expression of CREB target genes, including Bdnf and Bcl-2. These genes are known to regulate cell survival and differentiation, and may contribute to the observed increase in hippocampal neurogenesis, although further study is necessary to confirm this hypothesis. This work indicates that CREB family proteins are important regulators of hippocampal neurogenesis and behaviors associated with antidepressant response. However, behavioral results suggest that CREB in the hippocampus may not be necessary for the behavioral response to antidepressants, challenging a previous study that suggested increased CREB activity was sufficient to produce an antidepressant behavioral response. This mouse model of specific loss of CREB function will be useful in dissecting the role of CREB in specific brain regions, potentially resolving this discrepancy. Overall, future study of the role of CREB and its targets in the downstream mechanisms of antidepressant response may contribute to the development of novel therapeutics
New Limits on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales
We update the limit from the 90 GHz PIQUE ground-based polarimeter on the
magnitude of any polarized anisotropy of the cosmic microwave radiation. With a
second year of data, we have now limited both Q and U on a ring of 1 degree
radius. The window functions are broad: for E-mode polarization, the effective
l is = 191 +143 -132. We find that the E-mode signal can be no greater than
8.4 microK (95% CL), assuming no B-mode polarization. Limits on a possible
B-mode signal are also presented.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter
The significance of nitrogen fixation to new production during early summer in the Baltic Sea.
Rates of dinitrogen (N2) fixation and primary production were measured during two 9 day transect cruises in the Baltic proper in June–July of 1998 and 1999. Assuming that the early phase of the bloom of cyanobacteria lasted a month, total rates of N2 fixation contributed 15 mmol N m−2 (1998) and 33 mmol N m−2 (1999) to new production (sensu Dugdale and Goering, 1967). This constitutes 12–26% more new N than other annual estimates (mid July–mid October) from the same region. The between-station variability observed in both total N2 fixation and primary productivity greatly emphasizes the need for multiple stations and seasonal sampling strategies in biogeochemical studies of the Baltic Sea. The majority of new N from N2 fixation was contributed by filamentous cyanobacteria. On average, cyanobacterial cells >20 µm were able to supply a major part of their N requirements for growth by N2 fixation in both 1998 (73%) and 1999 (81%). The between-station variability was high however, and ranged from 28–150% of N needed to meet the rate of C incorporation by primary production. The molar C:N rate incorporation ratio (C:NRATE) in filamentous cyanobacterial cells was variable (range 7–28) and the average almost twice as high as the Redfield ratio (6.6) in both years. Since the molar C:N mass ratio (C:NMASS) in filamentous cyanobacterial cells was generally lower than C:NRATE at a number of stations, we suggest that the diazotrophs incorporated excess C on a short term basis (carbohydrate ballasting and buoyancy regulation), released nitrogen or utilized other regenerated sources of N nutrients. Measured rates of total N2 fixation contributed only a minor fraction of 13% (range 4–24) in 1998 and 18% (range 2–45) in 1999 to the amount of N needed for the community primary production. An average of 9 and 15% of total N2 fixation was found in cells <5 µm. Since cells <5 µm did not show any detectable rates of N2 fixation, the 15N-enrichment could be attributed to regenerated incorporation of dissolved organic N (DON) and ammonium generated from larger diazotroph cyanobacteria. Therefore, N excretion from filamentous cyanobacteria may significantly contribute to the pool of regenerated nutrients used by the non-diazotroph community in summer. Higher average concentrations of regenerated N (ammonium) coincided with higher rates of N2 fixation found during the 1999 transect and a higher level of 15N-enrichment in cells <5 µm. A variable but significant fraction of total N2 fixation (1–10%) could be attributed to diazotrophy in cells between 5–20 µm
Schistosoma mansoni Infection in Finchaa Sugar Estate: Public health Problem Assessment based on Clinical Records and Parasitological Surveys, Western Ethiopia
The survey of Schistosoma mansoni (S. mansoni) in Finchaa Sugar Estate, Western Ethiopia, was conducted to investigate the prevalence and health problems of schistosomiasis with some of the risk factors. The examination was undertaken based on the analysis of retrospective clinical data from the health center and a cross-sectional parasitological examinations using Kato-thick smear slides in April-June 2012/2013. Over the period 2008 to 2013 average prevalence among suspected patients at the health centre was 30.9%. Examination of double kato-thick smear slides from a random sample of 602 individuals from most schistosomiasis affected camp 7 revealed the prevalence of 37.5%. S. mansoni infection is become a year-round public health problem in Finchaa, Sugar Estate possibly due to permanent streams, water bodies and water contact behaviors and also reduced effectiveness of current control measures. Among the 7th camps, village A (camp 7) is the most schistosomiasis affected area (37.5%) followed by Kuyisa (25%). This is attributed to the presence of permanent stream (Fekerie stream) near camp 7. The present finding shows that the prevalence and intensity of schistosomiasis in the more affected camp 7 of Finchaa Sugar Estate was significantly higher among males than in females and its prevalence and intensity was found to be higher among study population within the age group of 11-20 years old. This study indicates that schistosomiasis is a major health problem in Finchaa Sugar Estate with moderate prevalence. The study results will provide an additional clinical and parasitological data on the current status of S. mansoni in Finchaa Sugar Estate and could serve as a guide in designing, developing and implementing intervention strategies to mitigate morbidity due to S. mansoni especially in highly risk groups under the Ethiopian health service system.Keywords: Egg per gram; Finchaa Sugar Estate; Kato-katz; Schistosomiasis; S. mansoni; Public healt
COMPASS: a 2.6m telescope for CMBR polarization studies
COMPASS (COsmic Microwave Polarization at Small Scale) is an experiment devoted to measuring the polarization of the CMBR. Its design and characteristics are presented
A Limit on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales
A ground-based polarimeter, PIQUE, operating at 90 GHz has set a new limit on
the magnitude of any polarized anisotropy in the cosmic microwave background.
The combination of the scan strategy and full width half maximum beam of 0.235
degrees gives broad window functions with average multipoles, l = 211+294-146
and l = 212+229-135 for the E- and B-mode window functions, respectively. A
joint likelihood analysis yields simultaneous 95% confidence level flat band
power limits of 14 and 13 microkelvin on the amplitudes of the E- and B-mode
angular power spectra, respectively. Assuming no B-modes, a 95% confidence
limit of 10 microkelvin is placed on the amplitude of the E-mode angular power
spectrum alone.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter
Fine-scale in situ measurements of oxygen distribution in marine sediments
A new profiling bottom lander (Profiluren) mounted with microelectrodes can measure oxygen profiles through the undisturbed sediment-water interface with 25-50 µm spatial resolution. The high spatial resolution of the in situ profiles reveal the thickness of the diffusive boundary layer (DBL) and allow calculations of: 1) the diffusive oxygen flux through the DBL, 2) the limitation of mass transfer between sediment and water due to the DBL and, 3) the oxygen consumption in discrete layers of the mm thick aerobic zone of marine sediments. The lander is thus an excellent tool for in situ analysis of oxygen dynamics at the sediment-water interface. Here we demonstrate two in situ oxygen profiles from a Danish coastal sediment at 15 m water depth, and discuss the impact of high resolution oxygen measurements
The effects of chest wall loading on perceptions of fatigue, exercise performance, pulmonary function, and muscle perfusion.
BACKGROUND: Load carriage (LC), which directly affects the chest wall and locomotor muscles, has been suggested to alter the ventilatory and circulatory responses to exercise, leading to increased respiratory muscle work and fatigue. However, studies exploring the impact of LC on locomotion increased internal work, complicating their interpretation. To overcome this issue, we sought to determine the effect of chest wall loading with restriction (CWL + R) on cycling performance, cardiopulmonary responses, microvascular responsiveness, and perceptions of fatigue. METHODS: In a randomized crossover design, 23 young healthy males (22 \ub1 4 years) completed a 5 km cycling time trial (TT) in loaded (CWL + R; tightened vest with 10% body weight) and unloaded conditions. After baseline pulmonary function testing (PFT; forced expiratory volume in 1 s, FEV1; forced vital capacity, FVC), cardiopulmonary indices (HR, heart rate; O2 uptake, VO2; ventilation, VE; tidal volume, VT; and breathing frequency, Bf), rating of perceived exertion (RPE), lactate (BLa), and microvascular responses (oxy-, deoxy-, total hemoglobin; and tissue saturation; StO2) of the vastus lateralis using near infrared spectroscopy were collected during the TT; and PFT was repeated post-exercise. RESULTS: Pre-exercise, CWL + R reduced (p < 0.05) FVC (5.6 \ub1 0.8 versus 5.5 \ub1 0.7 L), FEV1 (4.8 \ub1 0.7 versus 4.7 \ub1 0.6 L), and FEV1/FVC (0.9 \ub1 0.1 versus 0.8 \ub1 0.1). CWL + R modified power output (PO) over time (interaction, p = 0.02), although the 5 km time (461 \ub1 24 versus 470 \ub1 27 seconds), VT (3.0 \ub1 0.3 versus 2.8 \ub1 0.8 L), Bf, VE, HR, VO2, microvascular and perceptual (visual analog scale, or VAS, and RPE) responses were unchanged (p > 0.05). CWL + R increased (p < 0.05) the average BLa (7.6 \ub1 2.6 versus 8.6 \ub1 3 mmol/L). CONCLUSIONS: Modest CWL + R negatively affects pre-exercise pulmonary function, modifies cycling power output over time, and increases lactate production during a 5 km cycling trial, although the cardiorespiratory, microvascular, and perceptual responses were unaffected
Breaking the Redshift Deadlock - I: Constraining the star formation history of galaxies with sub-millimetre photometric redshifts
Future extragalactic sub-millimetre and millimetre surveys have the potential
to provide a sensitive census of the level of obscured star formation in
galaxies at all redshifts. While in general there is good agreement between the
source counts from existing SCUBA (850um) and MAMBO (1.25mm) surveys of
different depths and areas, it remains difficult to determine the redshift
distribution and bolometric luminosities of the sub-millimetre and millimetre
galaxy population. This is principally due to the ambiguity in identifying an
individual sub-millimetre source with its optical, IR or radio counterpart
which, in turn, prevents a confident measurement of the spectroscopic redshift.
Additionally, the lack of data measuring the rest-frame FIR spectral peak of
the sub-millimetre galaxies gives rise to poor constraints on their rest-frame
FIR luminosities and star formation rates. In this paper we describe
Monte-Carlo simulations of ground-based, balloon-borne and satellite
sub-millimetre surveys that demonstrate how the rest-frame FIR-sub-millimetre
spectral energy distributions (250-850um) can be used to derive photometric
redshifts with an r.m.s accuracy of +/- 0.4 over the range 0 < z < 6. This
opportunity to break the redshift deadlock will provide an estimate of the
global star formation history for luminous optically-obscured galaxies [L(FIR)
> 3 x 10^12 Lsun] with an accuracy of 20 per cent.Comment: 14 pages, 22 figures, submitted to MNRAS, replaced with accepted
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