Disconnection in the Alexandroff duplicate

[EN] It was demonstrated in [2] that the Alexandroff duplicate of the Čech-Stone compactification of the naturals is not extremally disconnected. The question was raised as to whether the Alexandroff duplicate of a non-discrete extremally disconnected space can ever be extremally disconnected. We answer this question in the affirmative; an example of van Douwen is significant. In a slightly different direction we also characterize when the Alexandroff duplicate of a space is a P-space as well as when it is an almost P-space.Bhattacharjee, P.; Knox, ML.; Mcgovern, WW. (2021). Disconnection in the Alexandroff duplicate. Applied General Topology. 22(2):331-344. https://doi.org/10.4995/agt.2021.14602OJS331344222P. Alexandrov and P. Urysohn, Memoire sur les espaces topologiques compacts, Verh. Akad. Wetensch. Amsterdam, 14 (1929), 1-96.K. Almontashery and L. Kalantan, Results about the Alexandroff duplicate space, Appl. Gen. Topol. 17, no. 2 (2016), 117-122. https://doi.org/10.4995/agt.2016.4521A. V. Arkhangel'skii, Topological Function Spaces, Mathematics and Its Applications, 78, Springer, Netherlands, 1992. https://doi.org/10.1007/978-94-011-2598-7G. Bezhanishvili, N. Bezhanishvili, J. Lucero-Bryan and J. van Mill, S4.3 and hereditarily extremally disconnected spaces, Georgian Mathematical Journal 22, no. 4 (2015), 469-475. https://doi.org/10.1515/gmj-2015-0041A. Caserta and S. Watson, The Alexandroff duplicate and its subspaces, Appl. Gen. Topol. 8, no. 2 (2007), 187-205. https://doi.org/10.4995/agt.2007.1880R. Engelking, On functions defined on Cartesian products, Fund. Math. 59 (1966), 221-231. https://doi.org/10.4064/fm-59-2-221-231L. Gillman and M. Jerison, Rings of Continuous Functions, Graduate Texts in Mathametics, vol. 43, Springer Verlag, Berlin-Heidelberg-New York, 1976.E. van Douwen, Applications of maximal topologies, Topology Appl. 51 (1993), 125-139. https://doi.org/10.1016/0166-8641(93)90145-4J. van Mill, Weak P-points in Čech-Stone compactifications, Trans. Amer. Math. Soc. 273 (1982), 657-678. https://doi.org/10.2307/1999934J. L. Verner, Lonely points revisited, Comment. Math. Univ. Carolin. 54, no. 1 (2013), 105-110

Balloon Atrial Septostomy as Initial Therapy in Pediatric Pulmonary Hypertension

Balloon atrial septostomy is a palliative procedure currently used to bridge medically refractory pulmonary hypertension patients to lung transplantation. In the current report, we present balloon atrial septostomy as an initial therapy for high-risk pediatric pulmonary hypertension patients at our institution. Nineteen patients with median age of 4.3 years (range 0.1-14.3 years) underwent balloon atrial septostomy during initial admission for pulmonary hypertension. There were no procedural complications or deaths within 24 h of balloon atrial septostomy. Patients were followed for a median of 2.6 years (interquartile range 1.0-4.8 years). Three (16%) patients died, 3 (16%) underwent lung transplantation, and 1 (5%) underwent reverse Potts shunt. Transplant-free survival at 30 days, 1 year, and 3 years was 84%, 76%, and 67% respectively. This single-center experience suggests early-BAS in addition to pharmacotherapy is safe and warrants consideration in high-risk pediatric pulmonary hypertension patients

The classical ring of quotients of Cc(X)C_c(X)

[EN] We construct the classical ring of quotients of the algebra of continuous real-valued functions with countable range. Our construction is a slight modification of the construction given in [M. Ghadermazi, O.A.S. Karamzadeh, and M. Namdari, On the functionally countable subalgebra of C(X), Rend. Sem. Mat. Univ. Padova, to appear]. Dowker's example shows that the two constructions can be different.Bhattacharjee, P.; Knox, ML.; Mcgovern, WW. (2014). The classical ring of quotients of $C_c(X)$. Applied General Topology. 15(2):147-154. doi:http://dx.doi.org/10.4995/agt.2014.3181.SWORD147154152Hager, A. W., Kimber, C. M., & McGovern, W. W. (2005). Unique a-closure for some ℓ-groups of rational valued functions. Czechoslovak Mathematical Journal, 55(2), 409-421. doi:10.1007/s10587-005-0031-zHenriksen, M., & Woods, R. G. (2004). Cozero complemented spaces; when the space of minimal prime ideals of a C(X) is compact. Topology and its Applications, 141(1-3), 147-170. doi:10.1016/j.topol.2003.12.004Knox, M. L., & McGovern, W. W. (2008). Rigid extensions of ℓ-groups of continuous functions. Czechoslovak Mathematical Journal, 58(4), 993-1014. doi:10.1007/s10587-008-0064-1R. Levy and M. D. Rice, Normal $P$-spaces and the $G_delta$-topology, Colloq. Math. 44, no. 2 (1981), 227-240.Levy, R., & Shapiro, J. (2005). Rings of quotients of rings of functions. Topology and its Applications, 146-147, 253-265. doi:10.1016/j.topol.2003.03.003A. Mysior, Two easy examples of zero-dimensional spaces, Proc. Amer. Math. Soc. 92, no. 4 (1984), 615-617.Porter, J. R., & Woods, R. G. (1988). Extensions and Absolutes of Hausdorff Spaces. doi:10.1007/978-1-4612-3712-9Rudin, W. (1957). Continuous functions on compact spaces without perfect subsets. Proceedings of the American Mathematical Society, 8(1), 39-39. doi:10.1090/s0002-9939-1957-0085475-

Exploring Pathways into and out of Amphetamine Type Stimulant use at Critical Turning Points: A Qualitative Interview Study

Amphetamine Type Stimulants (ATS) are increasingly used drugs globally. There is limited evidence about what shapes ATS use at critical turning points located within drug using pathways. Using turning point theory, as part of a life course approach, the ATTUNE study aimed to understand which social, economic and individual factors shape pathways into and out of ATS use. Qualitative, semi-structured interviews (n=70) were undertaken with individuals who had used ATS, or who had been exposed to them at least once in their lifetime. Our findings show that turning points for initiation were linked to pleasure, curiosity, boredom and declining mental health; increased use was linked to positive effects experienced at initiation and multiple life-stressors, often leading to more intense use. Decreased use was prompted by pivotal events (e.g. imprisonment) and sustained through continued wellbeing, day-to-day structure, and non-using social networks. We argue that the heterogeneity of these individuals challenges stereotypes of stimulant use allied to nightclubs and ‘hedonism’. Further, even at critical turning points for recovery, the use of services for problematic ATS consumption was low because users prioritised their alcohol or opioid use when seeking help. There is a need to develop service provision, training, and better outreach to individuals who need support at critical turning points

Exploring the intersections between Novel Psychoactive Substances (NPS) and other substance use in a police custody suite setting in the North East of England

Aims: Novel psychoactive substances (NPS), a range of plant-based/synthetic substances that mimic effects of other illicit substances (e.g. cannabis), are now illegal in the United Kingdom (May 2016) to produce/supply. Negative behavioural consequences of NPS use mean that users frequently transgress the law are arrested and detained in police custody suites. Evidence shows a link between traditional substance use and offending behaviour, with significant police time spent on alcohol-related incidents. We explore the intersections between NPS and other substances with police staff and users in custody; specifically the similarities and differences in treatment, management and policing of these substances. Methods: A qualitative study using semistructured interviews and thematic analysis. We recruited 15 police staff (4 women/11 men) and 25 NPS users (9 women/16 men). Results: Police staff perceived NPS users to be extremely volatile in custody and reported feeling less knowledgeable about how to manage and respond to their needs compared to other substance users (e.g. alcohol, heroin). Users rarely took NPS in isolation and often compared them to other illicit substances, balancing effects versus costs. Conclusion: NPS use has a striking effect on custody work, primarily because of unpredictable user behaviour, adding further pressure to already overstretched police staff

The effectiveness of psychosocial interventions at reducing the frequency of alcohol and drug use in parents: findings of a Cochrane review and meta‐analyses

Background and aim Parental substance use is a major public health and safeguarding concern. There have been a number of trials examining interventions targeting this risk factor. We aimed to estimate the effectiveness of psychosocial interventions at reducing parental substance use. Design We used systematic methods to identify trials; pooling data using a random-effects model. Moderator analyses examined influence of parent gender, presence of child in treatment, and intervention type. Setting No restrictions on setting. Participants Substance using parents of children below the age of 21 years. Interventions Psychosocial interventions including those that targeted drug and alcohol use only, and drug and alcohol use in combination with associated issues. Measurements Frequency of alcohol use and frequency of drug use. Findings We included 8 unique studies with a total of 703 participants. Psychosocial interventions were more effective at reducing the frequency of parental alcohol use than comparison conditions at 6 month (SMD - 0.32, 95% CI -0.51 to -0.13, P = 0.001) and 12-month follow-up (SMD -0.25, 95% CI -0.47 to -0.03, P = 0.02), and frequency of parental drug use at 12 months only (SMD-0.21, 95% CI -0.41 to -0.01, P = 0.04). Integrated interventions which combined both parenting and substance use targeted components were effective at reducing the frequency of alcohol use (6 months: SMD -0.56, 95% CI -0.96 to -0.016, P = 0.006; 12 months: SMD -0.42, 95% CI -0.82 to -0.03, P = 0.04) and drug use (6 months: SMD -0.39, 95% CI -0.75 to -0.03, P = 0.04; 12 months: SMD -0.43, 95% CI -0.80 to -0.07, P = 0.02). Interventions targeting only substance use or parenting skills were not effective at reducing frequency of alcohol or drug use at either time point. Conclusion Psychosocial interventions should target both parenting and substance use in an integrated intervention

Biological Effects and Chemical Measurements in Irish Marine Waters

The overall aim of this project was to increase Ireland’s capacity for the generation of integrated monitoring of biological effects and chemical measurement data and for the completion of a pilot scale assessment of the quality of the Irish marine environment at a number of selected locations.Sea Change Strategy with the support of the Marine Institute and the Marine Research Sub Programme of the National Development Plan 2007-2013, and funding from the Environmental Protection Agency (EPA

Integration of biological effects, fish histopathology and contaminant measurements for the assessment of fish health: A pilot application in Irish marine waters

This study investigates the use of a weight of evidence (WOE) approach to evaluate fish health status and biological effects (BEs) of contaminants for assessment of ecosystem health and discusses its potential application in support of the Marine Strategy Framework Directive (MSFD). External fish disease, liver histopathology and several BEs of contaminant exposure including 7-ethoxy resorufin O-de-ethylase (EROD), acetylcholinesterase (AChE), bile metabolites, vitellogenin (VTG) and alkali labile phosphates (ALP) were measured in two flatfish species from four locations in Ireland. Contaminant levels in fish were generally low with PCBs in fish liver below OSPAR environmental assessment criteria (EAC). There were consistencies with low PCB levels, EROD and PAH bile metabolite levels detected in fish. Dab from Cork, Dublin and Shannon had the highest relative prevalence of liver lesions associated with the carcinogenic pathway. An integrated biomarker response (IBR) showed promise to be useful for evaluation of environmental risk, although more contaminant parameters in liver are required for a full assessment with the present study

Climate challenges, vulnerabilities, and food security

This paper identifies rare climate challenges in the long-term history of seven areas, three in the subpolar North Atlantic Islands and four in the arid-to-semiarid deserts of the US Southwest. For each case, the vulnerability to food shortage before the climate challenge is quantified based on eight variables encompassing both environmental and social domains. These data are used to evaluate the relationship between the “weight” of vulnerability before a climate challenge and the nature of social change and food security following a challenge. The outcome of this work is directly applicable to debates about disaster management policy