Search for Daily Modulation of MeV Dark Matter Signals with DAMIC-M.

Dark matter (DM) particles with sufficiently large cross sections may scatter as they travel through Earth's bulk. The corresponding changes in the DM flux give rise to a characteristic daily modulation signal in detectors sensitive to DM-electron interactions. Here, we report results obtained from the first underground operation of the DAMIC-M prototype detector searching for such a signal from DM with MeV-scale mass. A model-independent analysis finds no modulation in the rate of 1 e^{-} events with sidereal period, where a DM signal would appear. We then use these data to place exclusion limits on DM in the mass range [0.53,2.7] MeV/c^{2} interacting with electrons via a dark photon mediator. Taking advantage of the time-dependent signal we improve by ∼2 orders of magnitude on our previous limit obtained from the total rate of 1 e^{-} events, using the same dataset. This daily modulation search represents the current strongest limit on DM-electron scattering via ultralight mediators for DM masses around 1 MeV/c^{2}.

First Constraints from DAMIC-M on Sub-GeV Dark-Matter Particles Interacting with Electrons.

We report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed with an integrated exposure of 85.23 g days, and exploits the subelectron charge resolution and low level of dark current of DAMIC-M charge-coupled devices (CCDs). Dark-matter-induced ionization signals above the detector dark current are searched for in CCD pixels with charge up to 7e^{-}. With this dataset we place limits on dark matter particles of mass between 0.53 and 1000 MeV/c^{2}, excluding unexplored regions of parameter space in the mass ranges [1.6,1000] MeV/c^{2} and [1.5,15.1] MeV/c^{2} for ultralight and heavy mediator interactions, respectively.

Results on Low-Mass Weakly Interacting Massive Particles from an 11 kg d Target Exposure of DAMIC at SNOLAB.

We present constraints on the existence of weakly interacting massive particles (WIMPs) from an 11 kg d target exposure of the DAMIC experiment at the SNOLAB underground laboratory. The observed energy spectrum and spatial distribution of ionization events with electron-equivalent energies >200 eV_{ee} in the DAMIC CCDs are consistent with backgrounds from natural radioactivity. An excess of ionization events is observed above the analysis threshold of 50 eV_{ee}. While the origin of this low-energy excess requires further investigation, our data exclude spin-independent WIMP-nucleon scattering cross sections σ_{χ-n} as low as 3×10^{-41} cm^{2} for WIMPs with masses m_{χ} from 7 to 10 GeV c^{-2}. These results are the strongest constraints from a silicon target on the existence of WIMPs with m_{χ}<9 GeV c^{-2} and are directly relevant to any dark matter interpretation of the excess of nuclear-recoil events observed by the CDMS silicon experiment in 2013.

Constraints on Light Dark Matter Particles Interacting with Electrons from DAMIC at SNOLAB.

We report direct-detection constraints on light dark matter particles interacting with electrons. The results are based on a method that exploits the extremely low levels of leakage current of the DAMIC detector at SNOLAB of 2-6×10^{-22} A cm^{-2}. We evaluate the charge distribution of pixels that collect <10e^{-} for contributions beyond the leakage current that may be attributed to dark matter interactions. Constraints are placed on so-far unexplored parameter space for dark matter masses between 0.6 and 100 MeV c^{-2}. We also present new constraints on hidden-photon dark matter with masses in the range 1.2-30 eV c^{-2}.

International consensus criteria for diagnosing and staging hand-arm vibration syndrome.

PURPOSE: In the 30 years since the Stockholm Workshop Scale (SWS) was published, the scientific literature on hand-arm vibration syndrome (HAVS) has grown and experience has been gained in its practical application. This research was undertaken to develop an up-to-date evidence-based classification for HAVS by seeking consensus between experts in the field. METHODS: Seven occupational physicians who are clinically active and have had work published on HAVS in the last 10 years were asked to independently take part in a three-round iterative Delphi process. Consensus was taken when 5/7 (72%) agreed with a particular statement. Experts were asked to provide evidence from the literature or data from their own research to support their views. RESULTS: Consensus was achieved for most of the questions that were used to develop an updated staging system for HAVS. The vascular and neurological components from the SWS are retained, but ambiguous descriptors and tests without adequately developed methodology such as tactile discrimination, or discriminating power such as grip strength, are not included in the new staging system. A blanching score taken from photographs of the hands during vasospastic episodes is recommended in place of self-recall and frequency of attacks to stage vascular HAVS. Methods with the best evidence base are described for assessing sensory perception and dexterity. CONCLUSIONS: A new classification has been developed with three stages for the clinical classification of vascular and neurological HAVS based on international consensus. We recommend it replaces the SWS for clinical and research purposes.

Dark Matter Search Results from the PICO-60 C_{3}F_{8} Bubble Chamber.

New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C_{3}F_{8} located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C_{3}F_{8} exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4×10^{-41} cm^{2} for a 30-GeV c^{-2} WIMP, more than 1 order of magnitude improvement from previous PICO results.

First Direct-Detection Constraints on eV-Scale Hidden-Photon Dark Matter with DAMIC at SNOLAB.

We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30 eV c^{-2} with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter κ is competitive with constraints from solar emission, reaching a minimum value of 2.2×10^{-14} at 17 eV c^{-2}. These results are the most stringent direct detection constraints on hidden-photon dark matter in the galactic halo with masses 3-12 eV c^{-2} and the first demonstration of direct experimental sensitivity to ionization signals <12 eV from dark matter interactions.

Threats to intact tropical peatlands and opportunities for their conservation.

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza-Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land-use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon-dense (domed pole forest) areas. New carbon-based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.

Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber.

New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of <3.5×10(-10) and an alpha rejection factor of >98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

Development of 'gastrostomy tube - is it for me?', a web-based patient decision aid for people living with motor neurone disease considering having a gastrostomy tube placed.

Objective: To develop and pilot a web-based patient decision aid (PDA) to support people living with motor neurone disease (plwMND) considering having a gastrostomy tube placed. Methods: In Phase 1, content and design were informed by semi-structured interviews, literature reviews and a prioritization survey. In Phase 2, the prototype PDA was tested with users and developed iteratively with feedback from surveys and 'think-aloud' interviews. Phase 1 and 2 participants were plwMND, carers and healthcare professionals (HCPs). In Phase 3, the PDA was evaluated by plwMND using validated questionnaires and HCPs provided feedback in focus groups. Results: Sixteen plwMND, 16 carers and 25 HCPs took part in Phases 1 and 2. Interviews and the literature review informed a prioritization survey with 82 content items. Seventy-seven per cent (63/82) of the content of the PDA was retained. A prototype PDA, which conforms to international standards, was produced and improved during Phase 2. In Phase 3, 17 plwMND completed questionnaires after using the PDA. Most plwMND (94%) found the PDA completely acceptable and would recommend it to others in their position, 88% had no decisional conflict, 82% were well prepared and 100% were satisfied with their decision-making. Seventeen HCPs provided positive feedback and suggestions for use in clinical practice. Conclusion: Gastrostomy Tube: Is it for me? was co-produced with stakeholders and found to be acceptable, practical and useful. Freely available from the MND Association website, the PDA is a valuable tool to support the shared decision-making process for gastrostomy tube placement.

Mid-infrared study of deoxycytidine at high pressures: evidence of a phase transition.

Room temperature mid-infrared experiments between 600 and 1600 cm(-1) have been performed on crystalline deoxycytidine as a function of pressure up to about 10 GPa. The wavenumbers of most vibrational modes shift to higher values with increasing pressures except for a mode near 840 cm(-1). Assignments for the observed modes are made on the basis of work published in the literature. Several anomalies are noted near 4.7 GPa, suggesting a phase transition. Our results for deoxycytidine are compared to similar measurements on cytidine.

Carpal tunnel syndrome in association with hand-arm vibration syndrome: a review of claimants seeking compensation in the Mining Industry.

Twenty six thousand eight hundred and forty-two miners seeking compensation were clinically assessed for vascular and neurosensory impairment arising from exposure to occupational hand-arm vibration (Hand-Arm Vibration Syndrome). They were also assessed clinically for Carpal Tunnel Syndrome which, if present, would result in additional compensation. Fifteen per cent were assessed as having both HAVS and CTS. Thirty-eight per cent of claimants had nocturnal wakening, 1.3% wasting of abductor pollicis brevis, 15% had a positive Tinel's test and 20% had a positive Phalen's test. The 15% prevalence reported is lower than the rates cited previously in several small population studies of workers exposed to vibration. This paper reports the results of the assessment process and discusses the difficulty of discriminating Carpal Tunnel Syndrome from diffuse neurosensory impairment arising from HAVS.

Medical direction in long-term care.

This report presents the views of over 1000 administrators, nurses and physicians with respect to the responsibilities, authority and impact of the medical director in a long-term care facility (LTCF), as well as the nature and future of long-term care and geriatric medicine in the USA. Nurses, administrators and physicians were more able to agree on the bureaucratic functions of the medical director than on the functions which might be considered more clinical or activist in terms of the total needs of the LTCF. There was no consensus about the external factors which might determine the future of LTC, i.e. alternatives to institutionalization, public attitudes or community hospital relations. Instead, concern seemed to focus upon the "low level" of funding for LTC. With respect to the nature of LTC itself, most respondents felt that the area was clinically challenging. However, only 40 percent of the physicians believed that clinical skills were more important than a sympathetic regard for patients. As a corollary, physicians were the least supportive of geriatrics as a new specialty in medicine.

A survey of the prescribing and administration of drugs in a long-term care institution for the elderly.

The prescription and administration of drugs (especially of the neuroactive class) was observed in 131 patients in an extended care facility. The average number of neuroactive drugs prescribed (2.1) was distinctly different from the average number administered (1.3) because of the large number of pro re nata (prn) prescriptions. More neuroactive substances were prescribed for patients with superior mentation and minimal physical disability; the difference between low and high groups was 1.7 (mentation) and 2.8 (physical status). The most common neuroactive drugs prescribed were: 1) analgesics, 2) major tranquilizers, and 3) hypnotics. Questionable prescribing practices were demonstrated by the fact that 30 patients had prescriptions for 38 "not-recommended"drugs; 23 of these prescriptions were for propoxyphene compound. After requiring physicians to rewrite drug orders every thirty days, a survey made ten months later showed that there was a decline (0.8) in the number of drugs prescribed per patient and a slight increase (0.45) in the number of drugs administered. Professional drug surveillance is crucial for improving the therapeutic process. At least two modifications of current prescribing practices are recommended: 1) a record should always be made of the precise condition(s) under which a drug prescribed "prn" is to be administered; and 2) a strong effort should be made to reduce the total number of drug prescriptions. The results of this survey suggest that certain procedural matters necessitating change are not in themselves the most substantive factors in improvement. Present "third party" review mechanisms likely will not ameliorate the current situation. It will be necessary to implement complex organizational changes in most extended care facilities.

Reliability of palpation of pedal pulses as ascertained by the kappa statistic.

An improved statistic (weighted Kappa) was tested for reviewing the reliability of the palpation of pedal pulses by three observers. Significant improvement was noted after training. Reliability also persisted with respect to a reduced form of the conventional ordinal grading system. The findings indicated that problems of usefulness or reliability may arise when more than five distinctions are made in describing the pulses or when the data are completely reduced to only a dichotomous (present-absent) system.

An assessment of the effects of exposure to vibration, smoking, alcohol and diabetes on the prevalence of Dupuytren's disease in 97,537 miners.

A consecutive sample of 97,537 miners seeking compensation for Hand-Arm Vibration Syndrome were examined in a medical assessment process which included documentation of age, hand dominance, Dupuytren's disease, years of vibration exposure, history of diabetes, smoking habits and units of alcohol consumption per week. The prime determinant of prevalence of Dupuytren's disease was age, and all other factors investigated were corrected for age. There was no statistically significant correlation between years of exposure to vibration and the prevalence of Dupuytren's disease. There was a statistically significant association with smoking, alcohol consumption and diabetes mellitus, with the heaviest smokers having an odds ratio (OR) of 1.31 (95% CI, 1.17, 1.47), the heaviest drinkers (in excess of 22 units a week) having an OR of 1.59 (95% CI, 1.47, 1.72) and diabetes mellitus patients having an increase in the odds of having Dupuytren's disease of 1.52 (95% CI 1.30, 1.77).