Recollements of Module Categories

We establish a correspondence between recollements of abelian categories up to equivalence and certain TTF-triples. For a module category we show, moreover, a correspondence with idempotent ideals, recovering a theorem of Jans. Furthermore, we show that a recollement whose terms are module categories is equivalent to one induced by an idempotent element, thus answering a question by Kuhn.Comment: Comments are welcom

Criteria for flatness and injectivity

Let $R$ be a commutative Noetherian ring. We give criteria for flatness of $R$-modules in terms of associated primes and torsion-freeness of certain tensor products. This allows us to develop a criterion for regularity if $R$ has characteristic $p$, or more generally if it has a locally contracting endomorphism. Dualizing, we give criteria for injectivity of $R$-modules in terms of coassociated primes and (h-)divisibility of certain \Hom-modules. Along the way, we develop tools to achieve such a dual result. These include a careful analysis of the notions of divisibility and h-divisibility (including a localization result), a theorem on coassociated primes across a \Hom-module base change, and a local criterion for injectivity.Comment: 19 page

Corrosione delle armature in calcestruzzo armato allo stadio G. Meazza di Milano - Il monitoraggio delle strutture del primo e del secondo anello

The structures of the three rings of the stadium "Giuseppe Meazza" in Milan, built in different stages from 1926 until 1990, is a remarkable evidence of the use of reinforced and prestressed concrete in the last century. If, on the one hand, these structures represent an icon for the potential of this material, on the other hand they also highlight its vulnerability. Reinforced concrete structures of the first and second rings are more than 60 years old and suffer from the effects of corrosion of the steel reinforcement. The municipality of Milan, being the owner of the stadium, has set up a collaboration with Politecnico di Milano aimed at the assessment of the conservation condition of the structures and planning of remedial works necessary to preserve and, at the same time, ensure the correct use of this important infrastructure. This paper describes the investigations carried out on the structures of the first and second ring (dating to 1926-37 and 1955 respectively), which allowed the definition of the extension of carbonation of concrete and the state of corrosion of the reinforcement. The opportunity to monitor the progress of the reinforcement corrosion was also highlighted in order to plan repair works. For this purpose, a monitoring system based on probes for measuring the corrosion potential of the reinforcement and electrical resistivity of concrete is under development

In the lycophyte Selaginella martensii is the "extra-qT" related to energy spillover? Insights into photoprotection in ancestral vascular plants

Lycophytes are early diverging vascular plants, representing a minor group as compared to the dominating euphyllophytes, mostly angiosperms. Having maximally developed in a CO2-rich atmosphere, extant lycophytes are characterized by a low carbon fixing capacity, which is compensated by a marked ability to induce the non-photochemical quenching of chlorophyll fluorescence (NPQ). Different kinetic components contribute to NPQ, in particular the fast relaxing high-energy quenching qE, the middle relaxing qT, and the slowly relaxing qI. Unlike angiosperms, lycophytes enhance the qT component under high light, originating from an "extra-qT". In this research, we analyze whether in Selaginella martensii the extra-qT can reflect a photosystem (PS) I-based quenching mechanism activated upon saturation of qE capacity. From comparative analyses of fluorescence quenching parameters, carbon fixation, in vivo low- and room-temperature fluorescence spectroscopy, and thylakoid protein phosphorylation, it is proposed that the extra-qT is not mechanistically separate from the ordinary qT. The results suggest a relationship between qT and photoprotective energy spillover to PSI, which is activated upon sensing the excitation energy pressure inside PSII and is possibly facilitated by phosphorylation of Lhcb6, a minor antenna protein of PSII. Energy spillover emphasizes 77K fluorescence emission from PSI core (F714) and becomes more relevant at irradiance levels corresponding to the CO2-limited, potentially photoinhibiting phase of photosynthesis. At the highest irradiances, when Lhcb6 phosphorylation potential has been saturated, the major LHCII increases in turn its phosphorylation level, probably leading to the full exploitation of PSI as a safe excitation sink. It is suggested that the low photosynthetic capacity of lycophytes could allow an easier experimental access to the use of PSI as a safe excitation quencher for PSII, a debated, emerging issue about thylakoid photoprotection in angiosperms.</p

What are the important factors in health-related quality of life for people with aphasia? A systematic review

Objective: To determine factors associated with or predictive of poor health-related quality of life (HRQL) in people with aphasia poststroke. Better understanding of these factors can allow better targeting of rehabilitation programs. Data Sources: Electronic databases, covering medical (eg, Medline, Excerpta Medica Database, Evidence-Based Medicine Reviews, Cumulative Index to Nursing and Allied Health Literature, Ovid, Allied and Complementary Medicine Database) and social sciences (eg, PsycINFO) were searched and key experts were approached. Study Selection: Studies including specific information on the HRQL of people with aphasia poststroke using validated HRQL measures or established ways of analyzing qualitative data were included. Two reviewers independently screened studies against the eligibility criteria. Data Extraction: This was undertaken independently by 2 reviewers. Discrepancies were resolved by consensus. Quantitative studies were assessed for quality with Counsell and Dennis' critical appraisal tool for systematic review of prognostic models in acute stroke; qualitative studies with the Critical Appraisal Skills Program tool for qualitative research. Data Synthesis: Fourteen research reports met the eligibility criteria. Because of their high heterogeneity, the data synthesis was narrative. The evidence is not strong enough to determine the main predictors of HRQL in people with aphasia. Still, emotional distress/depression, severity of aphasia and communication disability, other medical problems, activity limitations, and aspects of social network and support were important factors. Conclusions: Emotional distress, aphasia severity, communication and activity limitations, other medical problems, and social factors affect HRQL. Stroke HRQL studies need to include people with aphasia and report separately on them, in order to determine the main predictors of their HRQL and to identify what interventions can best address them

Ambient and substrate energy influence decomposer diversity differentially across trophic levels

The species-energy hypothesis predicts increasing biodiversity with increasing energy in ecosystems. Proxies for energy availability are often grouped into ambient energy (i.e., solar radiation) and substrate energy (i.e., non-structural carbohydrates or nutritional content). The relative importance of substrate energy is thought to decrease with increasing trophic level from primary consumers to predators, with reciprocal effects of ambient energy. Yet, empirical tests are lacking. We compiled data on 332,557 deadwood-inhabiting beetles of 901 species reared from wood of 49 tree species across Europe. Using host-phylogeny-controlled models, we show that the relative importance of substrate energy versus ambient energy decreases with increasing trophic levels: the diversity of zoophagous and mycetophagous beetles was determined by ambient energy, while non-structural carbohydrate content in woody tissues determined that of xylophagous beetles. Our study thus overall supports the species-energy hypothesis and specifies that the relative importance of ambient temperature increases with increasing trophic level with opposite effects for substrate energy

Ambient and substrate energy influence decomposer diversity differentially across trophic levels.

The species-energy hypothesis predicts increasing biodiversity with increasing energy in ecosystems. Proxies for energy availability are often grouped into ambient energy (i.e., solar radiation) and substrate energy (i.e., non-structural carbohydrates or nutritional content). The relative importance of substrate energy is thought to decrease with increasing trophic level from primary consumers to predators, with reciprocal effects of ambient energy. Yet, empirical tests are lacking. We compiled data on 332,557 deadwood-inhabiting beetles of 901 species reared from wood of 49 tree species across Europe. Using host-phylogeny-controlled models, we show that the relative importance of substrate energy versus ambient energy decreases with increasing trophic levels: the diversity of zoophagous and mycetophagous beetles was determined by ambient energy, while non-structural carbohydrate content in woody tissues determined that of xylophagous beetles. Our study thus overall supports the species-energy hypothesis and specifies that the relative importance of ambient temperature increases with increasing trophic level with opposite effects for substrate energy

Potential of a suite of robot/computer-assisted motivating systems for personalized, home-based, stroke rehabilitation

BACKGROUND: There is a need to improve semi-autonomous stroke therapy in home environments often characterized by low supervision of clinical experts and low extrinsic motivation. Our distributed device approach to this problem consists of an integrated suite of low-cost robotic/computer-assistive technologies driven by a novel universal access software framework called UniTherapy. Our design strategy for personalizing the therapy, providing extrinsic motivation and outcome assessment is presented and evaluated. METHODS: Three studies were conducted to evaluate the potential of the suite. A conventional force-reflecting joystick, a modified joystick therapy platform (TheraJoy), and a steering wheel platform (TheraDrive) were tested separately with the UniTherapy software. Stroke subjects with hemiparesis and able-bodied subjects completed tracking activities with the devices in different positions. We quantify motor performance across subject groups and across device platforms and muscle activation across devices at two positions in the arm workspace. RESULTS: Trends in the assessment metrics were consistent across devices with able-bodied and high functioning strokes subjects being significantly more accurate and quicker in their motor performance than low functioning subjects. Muscle activation patterns were different for shoulder and elbow across different devices and locations. CONCLUSION: The Robot/CAMR suite has potential for stroke rehabilitation. By manipulating hardware and software variables, we can create personalized therapy environments that engage patients, address their therapy need, and track their progress. A larger longitudinal study is still needed to evaluate these systems in under-supervised environments such as the home

Rehabilitation needs for older adults with stroke living at home: perceptions of four populations

<p>Abstract</p> <p>Background</p> <p>Many people who have suffered a stroke require rehabilitation to help them resume their previous activities and roles in their own environment, but only some of them receive inpatient or even outpatient rehabilitation services. Partial and unmet rehabilitation needs may ultimately lead to a loss of functional autonomy, which increases utilization of health services, number of hospitalizations and early institutionalization, leading to a significant psychological and financial burden on the patients, their families and the health care system. The aim of this study was to explore partially met and unmet rehabilitation needs of older adults who had suffered a stroke and who live in the community. The emphasis was put on needs that act as obstacles to social participation in terms of personal factors, environmental factors and life habits, from the point of view of four target populations.</p> <p>Methods</p> <p>Using the focus group technique, we met four types of experts living in three geographic areas of the province of Québec (Canada): older people with stroke, caregivers, health professionals and health care managers, for a total of 12 groups and 72 participants. The audio recordings of the meetings were transcribed and NVivo software was used to manage the data. The process of reducing, categorizing and analyzing the data was conducted using themes from the Disability Creation Process model.</p> <p>Results</p> <p>Rehabilitation needs persist for nine capabilities (e.g. related to behaviour or motor activities), nine factors related to the environment (e.g. type of teaching, adaptation and rehabilitation) and 11 life habits (e.g. nutrition, interpersonal relationships). The caregivers and health professionals identified more unmet needs and insisted on an individualized rehabilitation. Older people with stroke and the health care managers had a more global view of rehabilitation needs and emphasized the availability of resources.</p> <p>Conclusion</p> <p>Better knowledge of partially met or unmet rehabilitation needs expressed by the different types of people involved should lead to increased attention being paid to education for caregivers, orientation of caregivers towards resources in the community, and follow-up of patients' needs in terms of adjustment and rehabilitation, whether for improving their skills or for carrying out their activities of daily living.</p