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2.
Phys Rev Lett ; 130(3): 031803, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36763377

RESUMO

We estimate the maximum direct detection cross section for sub-GeV dark matter (DM) scattering off nucleons. For DM masses in the range 10 keV-100 MeV, cross sections greater than 10^{-36}-10^{-30} cm^{2} seem implausible. We present a DM candidate which realizes this maximum cross section: highly interactive particle relics (HYPERs). After HYPERs freeze-in, a dark sector phase transition decreases the mediator's mass. This increases the HYPER's direct detection cross section without impacting its abundance or measurements of big bang nucleosynthesis and the cosmic microwave background.

3.
Gen Psychiatr ; 33(1): e100149, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32175523

RESUMO

BACKGROUND: Reproducibility is a cornerstone of scientific advancement; however, many published works may lack the core components needed for study reproducibility. AIMS: In this study, we evaluate the state of transparency and reproducibility in the field of psychiatry using specific indicators as proxies for these practices. METHODS: An increasing number of publications have investigated indicators of reproducibility, including research by Harwicke et al, from which we based the methodology for our observational, cross-sectional study. From a random 5-year sample of 300 publications in PubMed-indexed psychiatry journals, two researchers extracted data in a duplicate, blinded fashion using a piloted Google form. The publications were examined for indicators of reproducibility and transparency, which included availability of: materials, data, protocol, analysis script, open-access, conflict of interest, funding and online preregistration. RESULTS: This study ultimately evaluated 296 randomly-selected publications with a 3.20 median impact factor. Only 107 were available online. Most primary authors originated from USA, UK and the Netherlands. The top three publication types were cohort studies, surveys and clinical trials. Regarding indicators of reproducibility, 17 publications gave access to necessary materials, four provided in-depth protocol and one contained raw data required to reproduce the outcomes. One publication offered its analysis script on request; four provided a protocol availability statement. Only 107 publications were publicly available: 13 were registered in online repositories and four, ten and eight publications included their hypothesis, methods and analysis, respectively. Conflict of interest was addressed by 177 and reported by 31 publications. Of 185 publications with a funding statement, 153 publications were funded and 32 were unfunded. CONCLUSIONS: Currently, Psychiatry research has significant potential to improve adherence to reproducibility and transparency practices. Thus, this study presents a reference point for the state of reproducibility and transparency in Psychiatry literature. Future assessments are recommended to evaluate and encourage progress.

5.
Phys Rev Lett ; 121(6): 061102, 2018 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-30141690

RESUMO

If dark matter stems from the background of a very light gauge boson, this gauge boson could exert forces on test masses in gravitational wave detectors, resulting in displacements with a characteristic frequency set by the gauge boson mass. We outline a novel search strategy for such dark matter, assuming the dark photon is the gauge boson of U(1)_{B} or U(1)_{B-L}. We show that both ground-based and future space-based gravitational wave detectors have the capability to make a 5σ discovery in unexplored parameter regimes.

6.
Curr Opin Pulm Med ; 21(6): 557-62, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26390338

RESUMO

PURPOSE OF REVIEW: To summarize recent primary publications and discuss the impact these finding have on current understanding on the development of hypoventilation in obesity hypoventilation syndrome (OHS), also known as Pickwickian syndrome. RECENT FINDINGS: As a result of the significant morbidity and mortality associated with OHS, evidence is building for pre-OHS intermediate states that can be identified earlier and treated sooner, with the goal of modifying disease course. Findings of alterations in respiratory mechanics with obesity remain unchanged; however, elevated metabolism and CO2 production may be instrumental in OHS-related hypercapnia. Ongoing positive airway pressure trials continue to demonstrate that correction of nocturnal obstructive sleep apnea and hypoventilation improves diurnal respiratory physiology, metabolic profiles, quality of life, and morbidity/mortality. Finally, CNS effects of leptin on respiratory mechanics and chemoreceptor sensitivity are becoming better understood; however, characterization remains incomplete. SUMMARY: OHS is a complex multiorgan system disease process that appears to be driven by adaptive changes in respiratory physiology and compensatory changes in metabolic processes, both of which are ultimately counter-productive. The diurnal hypercapnia and hypoxia induce pathologic effects that further worsen sleep-related breathing, resulting in a slowly progressive worsening of disease. In addition, leptin resistance in obesity and OHS likely contributes to blunting of ventilatory drive and inadequate chemoreceptor response to hypercarbia and hypoxemia.


Assuntos
Síndrome de Hipoventilação por Obesidade/etiologia , Animais , Humanos , Hipóxia/complicações , Leptina/metabolismo , Síndrome Metabólica/metabolismo , Síndrome de Hipoventilação por Obesidade/metabolismo , Síndrome de Hipoventilação por Obesidade/fisiopatologia , Qualidade de Vida , Apneia Obstrutiva do Sono/complicações
7.
Psychiatr Clin North Am ; 36(4): 533-44, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24229655

RESUMO

This article reviews some common medical conditions and the interaction between those illnesses and depression in the geriatric population. The authors aim to help clarify the 2-way interaction between depression and these medical conditions, especially in older individuals, and impart some important diagnostic and treatment considerations to the practicing physician. The presence of multiple conditions further complicates treatment, as does associated medication use, substance abuse problems (often underappreciated in the elderly), age-related changes in sleep architecture, and an array of other psychosocial and environmental factors that can contribute to the development of depression.


Assuntos
Doenças Cardiovasculares/epidemiologia , Transtorno Depressivo/epidemiologia , Doenças do Sistema Endócrino/epidemiologia , Insuficiência Renal Crônica/epidemiologia , Idoso , Comorbidade , Transtorno Depressivo/tratamento farmacológico , Gastroenteropatias/epidemiologia , Avaliação Geriátrica , Humanos , Masculino , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
8.
Phys Med Rehabil Clin N Am ; 23(4): 885-94, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23137743

RESUMO

Mobility-assistive technologies allow patients with neuromuscular disease to interact with peers and the community. In children, they also serve to facilitate development. Lack of access to appropriate assistive technology, especially in regards to mobility, can have adverse developmental consequences. There are multiple options for mobility devices and methods for their control. These devices can be integrated with other electronics to facilitate the control of a variety of devices in the environment. The clinician should assess which devices are best based on the patient's, caregivers', and medical team's goals.


Assuntos
Desenho de Equipamento , Limitação da Mobilidade , Doenças Neuromusculares/reabilitação , Interface Usuário-Computador , Cadeiras de Rodas , Auxiliares de Comunicação para Pessoas com Deficiência , Humanos , Doenças Neuromusculares/complicações , Posicionamento do Paciente , Postura
9.
Appl Spectrosc ; 61(4): 379-87, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17456256

RESUMO

The structure of two bisurea organogels was examined by Fourier-transform infrared (FT-IR) spectroscopy. Organogels were prepared in benzene at different concentrations of gelator in order to determine the effect of concentration on the assembly of organogelator molecules. This work examined two types of bisurea organogelators, both with dodecyl alkyl tail groups. The two molecules differ only in the length of an alkyl chain separating their two urea groups: 6 carbons in the C6C12 organogelator (1,6-bis(3(3,5-didodecoxybinzyl)-urea-hexane) and 12 carbons in the C12C12 organogelator (1,12-bis(3(3,5-didodecoxybinzyl)-urea-dodecane). The degree of urea hydrogen bonding was determined from the position of the amide II band, and the conformational order of the alkyl chains in the organogelator was determined in the methylene bending region. Both gels showed a general trend of less hydrogen bonding and greater conformational disorder in the alkyl chains as the concentration of organogelator increased; however, the changes were smaller in the C12C12 gels. This decrease in structural order with increasing organogelator concentration is explained by the kinetics of gel formation; more concentrated gels solidify too quickly to assemble perfectly. The observed differences between the two organogelators are caused by the different structures into which these two similar molecules assemble. The C6C12 organogelator only assembles linearly, while the C12C12 organogelator can form sheets through brick-like packing, and these packing motifs were confirmed by scanning electron microscopy.

10.
Phys Rev Lett ; 90(24): 241802, 2003 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-12857187

RESUMO

The little Higgs model provides an alternative to traditional candidates for new physics at the TeV scale. The new heavy gauge bosons predicted by this model should be observable at the CERN Large Hadron Collider (LHC). We discuss how the LHC experiments could test the little Higgs model by studying the production and decay of these particles.

11.
Phys Rev Lett ; 89(27): 271601, 2002 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-12513191

RESUMO

We present a model of leptogenesis that preserves lepton number. The model maintains the important feature of more traditional leptogenesis scenarios: The decaying particles that provide the CP violation necessary for baryogenesis also provide the explanation for the smallness of the neutrino Yukawa couplings. This model clearly demonstrates that, contrary to conventional wisdom, neutrinos need not be Majorana in nature in order to help explain the baryon asymmetry of the universe.

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