Glycolaldehyde, methyl formate and acetic acid adsorption and thermal desorption from interstellar ices

We have undertaken a detailed investigation of the adsorption, desorption and thermal processing of the astrobiologically significant isomers glycolaldehyde, acetic acid and methyl formate. Here, we present the results of laboratory infrared and temperature programmed desorption (TPD) studies of the three isomers from model interstellar ices adsorbed on a carbonaceous dust grain analogue surface. Laboratory infrared data show that the isomers can be clearly distinguished on the basis of their infrared spectra, which has implications for observations of interstellar ice spectra. Laboratory TPD data also show that the three isomers can be distinguished on the basis of their thermal desorption behaviour. In particular, TPD data show that the isomers cannot be treated the same way in astrophysical models of desorption. The desorption of glycolaldehyde and acetic acid from water-dominated ices is very similar, with desorption being mainly dictated by water ice. However, methyl formate also desorbs from the surface of the ice, as a pure desorption feature, and therefore desorbs at a lower temperature than the other two isomers. This is more clearly indicated by models of the desorption on astrophysical time-scales corresponding to the heating rate of 25 and 5 M⊙ stars. For a 25 M⊙ star, our model shows that a proportion of the methyl formate can be found in the gas phase at earlier times compared to glycolaldehyde and acetic acid. This has implications for the observation and detection of these molecules, and potentially explains why methyl formate has been observed in a wider range of astrophysical environments than the other two isomers

Trapping and desorption of complex organic molecules in water at 20 K

The formation, chemical and thermal processing of complex organic molecules (COMs) is currently a topic of much interest in interstellar chemistry. The isomers glycolaldehyde, methyl formate and acetic acid are particularly important because of their role as pre-biotic species. It is becoming increasingly clear that many COMs are formed within interstellar ices which are dominated by water. Hence the interaction of these species with water ice is crucially important in dictating their behaviour. Here we present the first detailed comparative study of the adsorption and thermal processing of glycolaldehyde, methyl formate and acetic acid adsorbed on and in water ices at astrophysically relevant temperatures (20 K). We show that the functional group of the isomer dictates the strength of interaction with water ice, and hence the resulting desorption and trapping behaviour. Furthermore, the strength of this interaction directly affects the crystallization of water, which in turn affects the desorption behaviour. Our detailed coverage and composition dependent data allow us to categorize the desorption behaviour of the three isomers on the basis of the strength of intermolecular and intramolecular interactions, as well as the natural sublimation temperature of the molecule. This categorization is extended to other C, H and O containing molecules in order to predict and describe the desorption behaviour of COMs from interstellar ices

Post-Operative Rehabilitation for Scapular Muscle Reattachment: A Case Report

Background and Purpose: Scapular muscle detachment is a rare orthopedic problem that has been described in the literature in patients following traumatic events involving traction, direct trauma, or a motor vehicle accident. The purpose of this case report is to describe the post-operative rehabilitation following scapular muscle reattachment surgery. Unique to this case report is the patient\u27s perspective, an orthopedic physical therapist with 25 years of experience. Case Description: A 47-year-old female physical therapist experienced a traction injury to bilateral upper extremities during a medical procedure resulting in bilateral rhomboid, and bilateral lower trapezius muscles were detached from the medial scapular border. Reconstruction of the left scapulothoracic musculature occurred five and one-half years post-injury with the right repaired one year later. This case report describes the rehabilitation program that took one-year to recover for each arm with a period of protected motion for 16-weeks and gradual return to function as a manual physical therapist over a period of one-year. Outcomes: The American Shoulder and Elbow Surgeons (ASES) Standardized Assessment Form and pain-free range of motion was used pre- and postoperatively. Left and right shoulder pre-operative ASES scores were 68 and 72, respectively. At the one-year post-operative the left shoulder was rated at 82 and the right shoulder was 90. Pain-free range of motion was achieved in both arms by one year. Functional limitations requiring strength overhead were the slowest to return and were not completely back at one year following either surgery. Discussion: Rehabilitation protocols for scapular muscle reattachment surgery are not commonly available to allow physical therapists to guide their patients and structure a rehabilitation program. This case report provides a sample pre-operative set of educational guidelines and a post-operative protocol for use after scapular reattachment surgery. This case report is unique because it offers a patient perspective who is a physical therapist and underwent this surgery twice. Therefore, providing insight on how to prepare for such a unique operation. The slow recovery is due to three issues 1) the prolonged time from injury to diagnosis created significant muscle wasting and muscular imbalance of surrounding tissues, 2) once this tissue was repaired it requires months of protection to recover, 3) the involved scapulothoracic muscle have to regain adequate strength as the foundation for upper extremity functions. Level of evidence: Level 5

Thermally induced mixing of water dominated interstellar ices

Despite considerable attention in the literature being given to the desorption behaviour of smaller volatiles, the thermal properties of complex organics, such as ethanol (C2H5OH), which are predicted to be formed within interstellar ices, have yet to be characterized. With this in mind, reflection absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD) have been used to probe the adsorption and desorption of C2H5OH deposited on top of water (H2O) films of various thicknesses grown on highly oriented pyrolytic graphite (HOPG) at 98 K. Unlike many other molecules detected within interstellar ices, C2H5OH has a comparable sublimation temperature to H2O and therefore gives rise to a complicated desorption pro. le. RAIRS and TPD show that C2H5OH is incorporated into the underlying ASW film during heating, due to a morphology change in both the C2H5OH and H2O ices. Desorption peaks assigned to C2H5OH co-desorption with amorphous, crystalline (CI) and hexagonal H2O-ice phases, in addition to C2H5OH multilayer desorption are observed in the TPD. When C2H5OH is deposited beneath ASW films, or is co-deposited as a mixture with H2O, complete co-desorption is observed, providing further evidence of thermally induced mixing between the ices. C2H5OH is also shown to modify the desorption of H2O at the ASW-CI phase transition. This behaviour has not been previously reported for more commonly studied volatiles found within astrophysical ices. These results are consistent with astronomical observations, which suggest that gas-phase C2H5OH is localized in hotter regions of the ISM, such as hot cores

The effects of methanol on the trapping of volatile ice components

The evaporation of icy mantles, which have been formed on the surface of dust grains, is acknowledged to give rise to the rich chemistry that has been observed in the vicinity of hot cores and corinos. It has long been established that water ice is the dominant species within many astrophysical ices. However, other molecules found within astrophysical ices, particularly methanol, can influence the desorption of volatile species from the ice. Here we present a detailed investigation of the adsorption and desorption of methanol-containing ices, showing the effect that methanol has on the trapping and release of volatiles from model interstellar ices. OCS and CO2 have been used as probe molecules since they have been suggested to reside in water-rich and methanol-rich environments. Experiments show that methanol fundamentally changes the desorption characteristics of both OCS and CO2, leading to the observation of mainly codesorption of both species with bulk water ice for the tertiary ices and causing a lowering of the temperature of the volcano component of the desorption. In contrast, binary ices are dominated by standard volcano desorption. This observation clearly shows that codepositing astrophysically relevant impurities with water ice, such as methanol, can alter the desorption dynamics of volatiles that become trapped in the pores of the amorphous water ice during the sublimation process. Incorporating experimental data into a simple model to simulate these processes on astrophysical timescales shows that the additional methanol component releases larger amounts of OCS from the ice mantle at lower temperatures and earlier times. These results are of interest to astronomers as they can be used to model the star formation process, hence giving information about the evolution of our Universe

The Commercial Sexual Exploitation and Sex Trafficking of Minors in the Boston Metropolitan Area: Experiences and Challenges Faced by Front-Line Providers and Other Stakeholders

Objectives: The commercial sexual exploitation of children (CSEC), including sex trafficking of minors, is considered a severe form of abuse and violence against minors. We use a public health lens to examine perceptions regarding the context and process of CSEC and sex trafficking of minors in the Boston area, the response of the health care sector, and opportunities to improve the health and well-being of exploited/trafficked minors. Methods: Using case study methodology, we conducted 22 semi-structured qualitative interviews of 25 key anti-trafficking stakeholders active in the Boston area. Results: Key informants identified CSEC involving boys, girls, and transgender youth as a local problem. Many social and economic factors facilitate sex trafficking, including child sexual abuse, domicile instability, and financial insecurity. The health needs of commercially sexually exploited minors are numerous, and local health care services are variable, particularly in the realm of mental health. Various factors function as barriers to a greater health care sector response, including low awareness of CSEC and sex trafficking of minors among health care providers. Gaps in CSEC prevention and response include early recognition of signs and symptoms, CSEC-knowledgeable trauma-sensitive health care services, and emergency shelter. Conclusions: CSEC, including sex trafficking of minors, is a recognized occurrence in the Boston area that requires a multidisciplinary response across multiple sectors. A more robust health care system response in coordination with other active stakeholders could help enhance the overall impact of local anti-CSEC/trafficking efforts. Increased health trainings, policy advocacy, and the use of multidisciplinary teams may be an effective way to partner across sectors and ensure wraparound services for exploited youth

Toward the Development of a Monitoring and Feedback System for Predicting Poor Adjustment to Grief

Losing a loved one is a fundamental and ubiquitous life experience that is often characterized by a certain period of grief and emotional distress. Although the majority of the bereaved can cope with grief resiliently, around 1 of 10 individuals could experience an unusually protracted and intense response referred to as prolonged grief disorder (PGD) following death of a loved one. PGD is associated with work and social impairment and heightened risk of severe medical and psychological conditions. Current means of diagnosis requires a minimum of 6 months to confirm and identify PGD and is discrepant with the fact that the bereaved may need psychotherapeutic intervention in a more timely manner. Contemporary studies have outlined prospective risk factors that could cause poor bereavement outcome, which can potentially contribute to early identification and prevention of problematic response to grief. Self-monitoring applications have been developed and broadly implemented in a vast spectrum of mental and health-related interventions and self-managing processes. This study presents the conceptualization and development of an Internet-based screening method designed by the researchers and psychotherapists that aims to provide meaningful and quantitative feedback in the early phase of the grief and to support decision making in the bereavement process through monitoring the susceptibility to problematic grief outcome