The Poker Face of Inelastic Dark Matter: Prospects at Upcoming Direct Detection Experiments

The XENON100 and CRESST experiments will directly test the inelastic dark matter explanation for DAMA's 8.9? sigma anomaly. This article discusses how predictions for direct detection experiments depend on uncertainties in quenching factor measurements, the dark matter interaction with the Standard Model and the halo velocity distribution. When these uncertainties are accounted for, an order of magnitude variation is found in the number of expected events at CRESST and XENON100.Comment: 5 pages, 3 figure

Isolation, X-ray Structures, and Electronic Spectra of Reactive Intermediates in Friedel−Crafts Acylations

Reactive intermediates in the Friedel−Crafts acylation of aromatic donors are scrutinized upon their successful isolation and X-ray crystallography at very low temperatures. Detailed analyses of the X-ray parameters for the [1:1] complexes of different aliphatic and aromatic-acid chlorides with the Lewis acids antimony pentafluoride and pentachloride, gallium trichloride, titanium and zirconium tetrachlorides provide unexpected insight into the activation mechanism for the formation of the critical acylium carbocations. Likewise, the X-ray-structure examinations of aliphatic and aromatic acylium electrophiles also isolated as crystalline salts point to the origins of their electrophilic reactivity. Although the Wheland intermediates (as acylium adducts to arene donors) could not be isolated in crystalline form owing to their exceedingly short lifetimes, transient (UV−vis) spectra of benzenium adducts of acylium carbocations with hexamethylbenzene can be measured and directly related to Wheland intermediates with other cationic electrophiles that have been structurally established via X-ray studies

Crystallographic Distinction between “Contact” and “Separated” Ion Pairs: Structural Effects on Electronic/ESR Spectra of Alkali-Metal Nitrobenzenides

The classic nitrobenzene anion-radical (NB-• or nitrobenzenide) is isolated for the first time as pure crystalline alkali-metal salts. The deliberate use of the supporting ligands 18-crown-6 and [2.2.2]cryptand allows the selective formation of contact ion pairs designated as (crown)M+NB-•, where M+ = K+, Rb+, and Cs+, as well as the separated ion pair K(cryptand)+NB-•both series of which are structurally characterized by precise low-temperature X-ray crystallography, ESR analysis, and UV−vis spectroscopy. The unusually delocalized structure of NB-• in the separated ion pair follows from the drastically shortened N−C bond and marked quinonoidal distortion of the benzenoid ring to signify complete (95%) electronic conjugation with the nitro substituent. On the other hand, the formation of contact ion pairs results in the substantial decrease of electronic conjugation in inverse order with cation size (K+ \u3e Rb+) owing to increased localization of negative charge from partial (NO2) bonding to the alkali-metal cation. Such a loss in electronic conjugation (or reverse charge transfer) may be counterintuitive, but it is in agreement with the distribution of odd-electron spin electron density from the ESR data and with the hypsochromic shift of the characteristic absorption band in the electronic spectra. Most importantly, this crystallographic study underscores the importance of ion-pair structure on the intrinsic property (and thus reactivity) of the component ions - as focused here on the nitrobenzenide anion

Isolation and X-ray Structures of Labile Benzoic- and Acetic-Acidium Carbocations

New carbocationic salts (via O-protonation of substituted benzoic acids) are prepared for the first time by controlled hydration of the corresponding benzoylium salts and isolated in pure crystalline form. Precise X-ray structural analyses reveal the rather unexpected (electronic) structure of the carboxylic-acidium functionality

Time Spent Working in Custody Influences Work Sample Test Battery Performance of Deputy Sheriffs Compared to Recruits

This study determined the influence of years spent working in custody on fitness measured by a state-specific testing battery (Work Sample Test Battery; WSTB) in deputy sheriffs. Retrospective analysis was conducted on one patrol school class (51 males, 13 females) divided into three groups depending on time spent working in custody: DS24 (<24 months; n = 20); DS2547 (25–47 months; n = 23); and DS48+ (≥48 months; n = 21). These groups were compared to a recruit class (REC; 219 males, 34 females) in the WSTB, which comprised five tasks completed for time: 99-yard (90.53-m) obstacle course (99OC); 165-pound (75-kg) dummy drag; six-foot (1.83-m) chain link fence (CLF) and solid wall (SW) climb; and 500-yard (457.2-m) run (500R). A univariate analysis of covariance (ANCOVA) (controlling for sex and age) with Bonferroni post hoc determined significant between-group differences. DS48+ were slower in the 99OC compared to the REC (p = 0.007) and performed the CLF and SW slower than all groups (p ≤ 0.012). DS24, DS2547, and DS48+ were all slower than REC in the 500R (p ≤ 0.002). Physical training should be implemented to maintain fitness and job-specific task performance in deputy sheriffs working custody, especially considering the sedentary nature of this work

Structural Effects of Carbon Monoxide Coordination to Carbon Centers. π and σ Bindings in Aliphatic Acyl \u3cem\u3eversus\u3c/em\u3e Aromatic Aroyl Cations

The binding of carbon monoxide to carbon centers has been examined with two series of aromatic and aliphatic oxocarbonium ions that are successfully isolated as crystalline and highly reactive (hygroscopic) aroylium and acylium salts with poorly coordinating counteranions. X-Ray crystallographic analyses at −150 °C afford precise structural parameters for the characteristic linear carbonyl bond (rCO) and the bond to the carbon centers (rCα). The correlations of these structural parameters evaluated for alkyl (Me, Et and i-Pr) and aryl (p-Me, 2,4,6-trimethyl, p-MeO and p-fluorophenyl) oxocarbonium ions with the corresponding carbonyl stretching frequencies in the solid-state (reflectance) IR spectra yield valuable insight into the binding mode of carbon monoxide. Most noteworthy is the synergic (π–σ) bonding in aroylium structures in contrast to the mainly σ bonding in acylium structures that are organic mimics for carbon monoxide bonding in classical and nonclassical metal carbonyls, respectively

Sex workers perspectives on strategies to reduce sexual exploitation and HIV risk: a qualitative study in Tijuana, Mexico.

Globally, female sex workers are a population at greatly elevated risk of HIV infection, and the reasons for and context of sex industry involvement have key implications for HIV risk and prevention. Evidence suggests that experiences of sexual exploitation (i.e., forced/coerced sex exchange) contribute to health-related harms. However, public health interventions that address HIV vulnerability and sexual exploitation are lacking. Therefore, the objective of this study was to elicit recommendations for interventions to prevent sexual exploitation and reduce HIV risk from current female sex workers with a history of sexual exploitation or youth sex work. From 2010-2011, we conducted in-depth interviews with sex workers (n = 31) in Tijuana, Mexico who reported having previously experienced sexual exploitation or youth sex work. Participants recommended that interventions aim to (1) reduce susceptibility to sexual exploitation by providing social support and peer-based education; (2) mitigate harms by improving access to HIV prevention resources and psychological support, and reducing gender-based violence; and (3) provide opportunities to exit the sex industry via vocational supports and improved access to effective drug treatment. Structural interventions incorporating these strategies are recommended to reduce susceptibility to sexual exploitation and enhance capacities to prevent HIV infection among marginalized women and girls in Mexico and across international settings