618 research outputs found
Dynamics of a structured slug population model in the absence of seasonal variation
We develop a novel, nonlinear structured population model for the slug Deroceras reticulatum, a highly significant agricultural pest of great economic impact, in both organic and non-organic settings. In the absence of seasonal variations, we numerically explore the effect of life history traits that are dependent on an individual's size and measures of population biomass. We conduct a systematic exploration of parameter space and highlight the main mechanisms and implications of model design. A major conclusion of this work is that strong size dependent predation significantly adjusts the competitive balance, leading to non-monotonic steady state solutions and slowly decaying transients consisting of distinct generational cycles. Furthermore, we demonstrate how a simple ratio of adult to juvenile biomass can act as a useful diagnostic to distinguish between predated and non-predated environments, and may be useful in agricultural settings
Synthesis Nano Zinc Oxide Materials and Their Activity on Fungus Growth
In this study Zinc oxide Nano particles was synthesized by employing sol-gel technique to explore novel antifungal agents to beat the developed of fungi resistance to many conventional fungicides .Prepared of Zinc oxide Nano particles were investigated via using Scanning Electron Microscopy (SEM, the VEGA Easy Probe), X ray powder diffraction (XRD) , FTIR spectrum, The antifungal properties of ZnO nanoparticles were tested against Fussarium spp., Alternaria spp. , Penicillium spp. , and Aspergillus spp. by using agar diffusion method. The percentage of growth was lowest comparison with control for all types of fungi when used zinc oxide Nano in different concentration
Open Gromov-Witten Invariants of Toric Calabi-Yau 3-Folds
We present a proof of the mirror conjecture of Aganagic-Vafa
[arXiv:hep-th/0012041] and Aganagic-Klemm-Vafa [arXiv:hep-th/0105045] on disk
enumeration in toric Calabi-Yau 3-folds for all smooth semi-projective toric
Calabi-Yau 3-folds. We consider both inner and outer branes, at arbitrary
framing. In particular, we recover previous results on the conjecture for (i)
an inner brane at zero framing in the total space of the canonical line bundle
of the projective plane (Graber-Zaslow [arXiv:hep-th/0109075]), (ii) an outer
brane at arbitrary framing in the resolved conifold (Zhou [arXiv:1001.0447]),
and (iii) an outer brane at zero framing in the total space of the canonical
line bundle of the projective plane (Brini [arXiv:1102.0281, Section 5.3]).Comment: 39 pages, 11 figure
Mathematical stories: Why do more boys than girls choose to study mathematics at AS-level in England?
Copyright @ 2005 Taylor & FrancisIn this paper I address the question: How is it that people come to choose mathematics and in what ways is this process gendered? I draw on the findings of a qualitative research study involving interviews with 43 young people all studying mathematics in post-compulsory education in England. Working within a post-structuralist framework, I argue that gender is a project and one that is achieved in interaction with others. Through a detailed reading of Toni and Claudiaâs stories I explore the tensions for young women who are engaging in mathematics, something that is discursively inscribed as masculine, while (understandably) being invested in producing themselves as female. I conclude by arguing that seeing âdoing mathematicsâ as âdoing masculinityâ is a productive way of understanding why mathematics is so male dominated and by looking at the implications of this understanding for gender and mathematics reform work.This work is funded by the ESR
Phase I clinical and pharmacokinetic study of PM01183 (a tetrahydroisoquinoline, Lurbinectedin) in combination with gemcitabine in patients with advanced solid tumors
Background To determine the recommended dose (RD) of a combination of PM01183 and gemcitabine in patients with advanced solid tumors. Methods Forty-five patients received escalating doses of PM01183/gemcitabine on Days 1 and 8 every 3Â weeks (d1,8 q3wk) following a standard 3Â +Â 3 design. Results PM01183 3.5Â mg flat dose (FD)/gemcitabine 1000Â mg/m(2) was the highest dose level tested. Dose-limiting toxicities (DLTs) were mostly hematological and resulted in the expansion of a lower dose level (PM01183 3.5Â mg FD/gemcitabine 800Â mg/m(2)); 19 patients at this dose level were evaluable but >30% had DLT and >20% had febrile neutropenia. No DLT was observed in 11 patients treated at PM01183 3.0Â mg FD/gemcitabine 800Â mg/m(2), which was defined as the RD. This regimen was feasible and tolerable with manageable toxicity; mainly grade 3/4 myelosuppression. Non-hematological toxicity comprised fatigue, nausea, vomiting, and transaminases increases. Fifteen (33%) patients received â„6Â cycles with no cumulative hematological toxicity. Pharmacokinetic analysis showed no evidence of drug-drug interaction. Nine of 38 patients had response as per RECIST (complete [3%] and partial [21%]), for an overall response rate (ORR) of 24% (95% Confidence Interval [CI] 12-40%). Eleven patients (29%) had disease stabilization â„4Â months. Responses were durable (median of 8.5Â months): overall median progression-free survival (PFS) was 4.2Â months (95% CI, 2.7-6.5Â months). Conclusions The RD for this combination is PM01183 3.0Â mg FD (or 1.6Â mg/m(2))/gemcitabine 800Â mg/m(2) d1,8 q3wk. This schedule is well tolerated and has antitumor activity in several advanced solid tumor types
The environmental impacts of biomass crops: use by birds of miscanthus in summer and winter in southwestern England
We compared birds in a group of established and well-managed miscanthus (Miscanthus x giganteus) fields in Somerset and East Devon, southwestern England, with plots of short rotation coppice (SRC) willow, arable crops and grassland in two winters and one summer. Following early spring cutting, 19 miscanthus fields grew taller, initially produced greater cover and were less weedy than SRC. As stubble in May, the miscanthus contained broadly similar species at similar densities to arable and grassland comparison plots. By July, at 2-m-tall, miscanthus held higher densities of birds but of fewer species, most of them characteristic of woodland and scrub. SRC, previously identified as being a beneficial crop for many birds, always contained more species and individuals than miscanthus. Throughout each of two winters, 15 miscanthus plots remained unharvested and contained more wood/scrub species such as Blackbirds Turdus merula, tits, Reed Buntings Emberiza schoeniclus and Woodcock Scolopax rusticola than the comparison plots, which held more corvids and Skylarks Alauda arvensis amongst others. Similar overall mean densities of birds in the miscanthus and the comparison plots masked relatively low density variance in miscanthus and very high variance in the comparison plots. Unharvested miscanthus crops grown in place of habitat types supporting flocks of wintering birds would displace these flocks. Miscanthus plantations with open patches attracted more finches and waders in winter. The two previous studies of birds in miscanthus in the UK found more species and more individuals than we did in summer and winter. Both these studies documented high levels of weediness and patchy crop growth. In the context of this previous work our data suggest that bird use of miscanthus in summer and winter is likely to be variable, affected by region, weediness, crop structure and patchiness. While large-scale cropping of SRC in England is likely to have a positive overall impact on a suite of common farmland and woodland birds, our data suggest that miscanthus in the southwest of England may have an approximately neutral effect. However, some open farmland specialist species may be lost when planting either crop
A Double-Blind, Placebo-Controlled Withdrawal Trial of Dexmethylphenidate Hydrochloride in Children with Attention Deficit Hyperactivity Disorder
Objectives:
d,l-threo-methylphenidate HCl (d,l-MPH) is the most common treatment of attention deficit
hyperactivity disorder (ADHD). A previous report showed placebo-controlled efficacy for the purified disomer
(dexmethylphenidate hydrochloride, d-MPH, Focalinâą) with a 2:1 potency compared to dl, and
suggested a 6-hour duration of action. This study complements that report by studying the effect of
placebo-controlled discontinuation and retesting the duration of action.
Methods:
A 6-week, open-label titration of d-MPH (2.5â10 mg twice-a-day) was followed by a doubleblind,
placebo-controlled, 2-week withdrawal study of responders.
Results:
In the open titration, 82% of the 89 enrolled patients achieved a Clinical Global Impressionâ
Improvement (CGI-I) rating of much or very much improved. Only 5 patients discontinued for adverse
events. Seventy-five patients continued into the placebo-controlled discontinuation. For the randomly
assigned d-MPH (n = 35) and placebo (n = 40) groups, mean ages, respectively, were 10.1 ± 2.9 and 9.9 ±
2.7 years, 86% and 78% were male, and 70.6% and 80.0% took the ceiling dose of 10 mg twice-daily,
respectively. Each group had 80% combined-type ADHD and 20% inattentive type. By the end of the 2-
week, placebo-masked withdrawal, significantly more placebo patients (24 of 39) than d-MPH continuers
(6 of 35) relapsed (61.5% versus 17.1%, p = 0.001). Compared to d-MPH continuers, placebo patients
deteriorated significantly more in the 2-week period on teacher ratings of the 18 ADHD symptoms rated 0â
3 (p = 0.028), the 3 p.m. and 6 p.m. parent ADHD symptom ratings (p = 0.0026 and p = 0.0381,
respectively), and clinic (2â3 p.m.) and home (6 p.m.) Math Tests (p = 0.024 and p < 0.0001, respectively).
The 6 p.m. scores replicated the significant effect at 6 hours reported in the previous study.
Conclusions:
d-MPH is safe, tolerable, and effective, with a 6-hour duration of effect suggested by the
significant difference from placebo at 6 hours on a double-blind discontinuation
De novo deletions and duplications of 17q25.3 cause susceptibility to cardiovascular malformations
BACKGROUND: Genomic disorders resulting from deletion or duplication of genomic segments are known to be an important cause of cardiovascular malformations (CVMs). In our previous study, we identified a unique individual with a de novo 17q25.3 deletion from a study of 714 individuals with CVM.
METHODS: To understand the contribution of this locus to cardiac malformations, we reviewed the data on 60,000 samples submitted for array comparative genomic hybridization (CGH) studies to Medical Genetics Laboratories at Baylor College of Medicine, and ascertained seven individuals with segmental aneusomy of 17q25. We validated our findings by studying another individual with a de novo submicroscopic deletion of this region from Cytogenetics Laboratory at Cincinnati Children's Hospital. Using bioinformatic analyses including protein-protein interaction network, human tissue expression patterns, haploinsufficiency scores, and other annotation systems, including a training set of 251 genes known to be linked to human cardiac disease, we constructed a pathogenicity score for cardiac phenotype for each of the 57 genes within the terminal 2.0 Mb of 17q25.3.
RESULTS: We found relatively high penetrance of cardiovascular defects (~60 %) with five deletions and three duplications, observed in eight unrelated individuals. Distinct cardiac phenotypes were present in four of these subjects with non-recurrent de novo deletions (range 0.08 Mb-1.4 Mb) in the subtelomeric region of 17q25.3. These included coarctation of the aorta (CoA), total anomalous pulmonary venous return (TAPVR), ventricular septal defect (VSD) and atrial septal defect (ASD). Amongst the three individuals with variable size duplications of this region, one had patent ductus arteriosus (PDA) at 8 months of age.
CONCLUSION: The distinct cardiac lesions observed in the affected patients and the bioinformatics analyses suggest that multiple genes may be plausible drivers of the cardiac phenotype within this gene-rich critical interval of 17q25.3
Modelling the production, profit, and greenhouse gas emissions of Irish sheep flocks divergent in genetic merit
peer-reviewedCONTEXTSheep production industries face the challenge of increasing farm production and profit while reducing environmental impacts. OBJECTIVESGenetic selection using multi-trait breeding indices can be used to improve flock productivity, profitability, and greenhouse gas (GHG) emissions intensities (kg CO2-eq /kg of product), however validation of the improved performance of animals ranked higher on breeding indices at a flock level is required. METHODSPhenotypic data from 387,580 production records of animals born between 2018 and 2020 of known genetic merit in commercial flocks were inputted to an established bio-economic model. Two contrasting flocks were compared, a flock of ewes ranked High (top 20%) on the Irish replacement Index bred with rams ranked High on the replacement and terminal indices, and a flock of ewes ranked Low (bottom 20%) on the Irish replacement Index bred with rams ranked Low on the replacement and terminal indices. The two flocks were then simulated using life cycle assessment to estimate the GHG emissions profile for both systems. RESULTS AND CONCLUSIONFlock weaning rates were 1.70 and 1.53 lambs weaned per ewe presented for breeding for the High and Low genetic merit flocks, respectively. The flock of High genetic merit ewes sold 0.17 more lambs per ewe, equating to 3.29 kg more lamb carcass per ewe, than the flock of Low genetic merit ewes; lambs from the High genetic merit flock were also sold at an earlier age. The greater production of the High genetic merit flocks resulted in an additional âŹ18/ewe net profit than the Low genetic merit flock. Although total flock GHG emissions were higher for the High genetic merit flock, GHG emissions intensities were lower at 21.7 and 23.3 kg CO2-eq /kg lamb carcass sold for the High and Low genetic merit flocks, respectively. The lower emissions intensity of the High genetic merit flock was due to the dilution effect of higher lamb production and lambs being drafted for slaughter ealier. SIGNIFICANCEThe results suggest Irish sheep producers can make substantial profit gains through selection according to the national breeding indices while also reducing their environmental impact, and farmers should consider genetic merit when purchasing their rams, particularly sires of replacement ewe lambs
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