The role of cutting fluids is well known for the importance of removing heat from the cutting edge, lubricating the sliding chip contact and transporting the metal chips away from the cutting zone. ...Dry machining leads to increased cutting temperatures and higher wear rates resulting in shorter tool life; this is particularly evident in the cutting of high strength materials. Diamond coated cutting inserts are not usually considered for machining titanium due to rapid oxidation of the coating at the temperatures typical of titanium machining. This paper examines the formation of hot-spots on the rake face during dry and near-dry turning of titanium using conventional cemented carbide inserts. Machining performance is assessed by measurement of tool wear and tool life. Trials with an internally cooled tool with a specially designed, diamond coated insert have shown that the heat from the cutting operation can be rapidly diffused over the entire surface of the insert and thus successfully drawn away from the tool via closed loop recirculation of coolant through the tool holder. This enables wear to be inhibited by management of rake face temperature to keep it below the critical temperatures at which these prominent wear mechanisms operate. Measurements of change in coolant temperature before and after circulation are used to quantify the heat removed from the cutting process. The low friction coefficient and high thermal conductivity of diamond, assisted by the indirect cooling, results in longer tool life whilst maintaining high standards of surface finish.
•The successful application of an internally cooled tool in dry cutting titanium.•Utilisation of a diamond coating as a heat dissipation and heat transfer layer.•Reduced cutting temperatures and improved tool life.
Rationale: Deep brain stimulation (DBS) of the hippocampus is proposed for enhancement of memory impaired by injury or disease. Many pre-clinical DBS paradigms can be addressed in epilepsy patients ...undergoing intracranial monitoring for seizure localization, since they already have electrodes implanted in brain areas of interest. Even though epilepsy is usually not a memory disorder targeted by DBS, the studies can nevertheless model other memory-impacting disorders, such as Traumatic Brain Injury (TBI). Methods: Human patients undergoing Phase II invasive monitoring for intractable epilepsy were implanted with depth electrodes capable of recording neurophysiological signals. Subjects performed a delayed-match-to-sample (DMS) memory task while hippocampal ensembles from CA1 and CA3 cell layers were recorded to estimate a multi-input, multi-output (MIMO) model of CA3-to-CA1 neural encoding and a memory decoding model (MDM) to decode memory information from CA3 and CA1 neuronal signals. After model estimation, subjects again performed the DMS task while either MIMO-based or MDM-based patterned stimulation was delivered to CA1 electrode sites during the encoding phase of the DMS trials. Each subject was sorted (
post hoc
) by prior experience of repeated and/or mild-to-moderate brain injury (RMBI), TBI, or no history (control) and scored for percentage successful delayed recognition (DR) recall on stimulated vs. non-stimulated DMS trials. The subject’s medical history was unknown to the experimenters until after individual subject memory retention results were scored. Results: When examined compared to control subjects, both TBI and RMBI subjects showed increased memory retention in response to both MIMO and MDM-based hippocampal stimulation. Furthermore, effects of stimulation were also greater in subjects who were evaluated as having pre-existing mild-to-moderate memory impairment. Conclusion: These results show that hippocampal stimulation for memory facilitation was more beneficial for subjects who had previously suffered a brain injury (other than epilepsy), compared to control (epilepsy) subjects who had not suffered a brain injury. This study demonstrates that the epilepsy/intracranial recording model can be extended to test the ability of DBS to restore memory function in subjects who previously suffered a brain injury other than epilepsy, and support further investigation into the beneficial effect of DBS in TBI patients.
Cardiovascular events are, after cancer, the most common cause of death in COPD patients. Arterial stiffness is an independent predictor of all-cause mortality and cardiovascular events. Several ...cross-sectional studies have confirmed increased arterial stiffness in patients with COPD. Various mechanisms in the development of arterial stiffness in COPD such as reduced lung function or systemic inflammation have been proposed. However, clinical predictors of arterial stiffness that had been reported in cross-sectional studies have not yet been confirmed in a longitudinal setting. We have assessed the course of augmentation index (AIx) - a measure of systemic arterial stiffness - and possible predictors in a cohort of COPD patients over a period of up to 7 years.
COPD patients underwent annual AIx measurement by applanation tonometry for a maximum duration of 7 years. Additionally, we performed annual assessments of lung function, blood gases, systemic inflammation, serum lipids and blood pressure. Associations between the course of AIx and potential predictors were investigated through a mixed effect model.
Seventy-six patients (mean (SD) age 62.4 (7.1), male 67%) were included. The AIx showed a significant annual increase of 0.91% (95% CI 0.21/1.60) adjusted for baseline. The change in diffusion capacity (DLco), low-density lipoprotein (LDL), and high-sensitivity c-reactive protein (hsCRP) was independently associated with the increasing evolution of AIx (Coef. - 0.10, p<0.001, Coef. 1.37, p=0.003, and Coef. 0.07, p=0.033, respectively).
This study demonstrated a meaningful increase in arterial stiffness in COPD over time. A greater annual increase in arterial stiffness was associated with the severity of emphysema (measured by DLco), systemic inflammation, and dyslipidaemia.
www.ClinicalTrials.gov, NCT01527773.
Here, we demonstrate the first successful use of static neural stimulation patterns for specific information content. These static patterns were derived by a model that was applied to a subject's own ...hippocampal spatiotemporal neural codes for memory.
We constructed a new model of processes by which the hippocampus encodes specific memory items via spatiotemporal firing of neural ensembles that underlie the successful encoding of targeted content into short-term memory. A memory decoding model (MDM) of hippocampal CA3 and CA1 neural firing was computed which derives a stimulation pattern for CA1 and CA3 neurons to be applied during the encoding (sample) phase of a delayed match-to-sample (DMS) human short-term memory task.
MDM electrical stimulation delivered to the CA1 and CA3 locations in the hippocampus during the sample phase of DMS trials facilitated memory of images from the DMS task during a delayed recognition (DR) task that also included control images that were not from the DMS task. Across all subjects, the stimulated trials exhibited significant changes in performance in 22.4% of patient and category combinations. Changes in performance were a combination of both increased memory performance and decreased memory performance, with increases in performance occurring at almost 2 to 1 relative to decreases in performance. Across patients with impaired memory that received bilateral stimulation, significant changes in over 37.9% of patient and category combinations was seen with the changes in memory performance show a ratio of increased to decreased performance of over 4 to 1. Modification of memory performance was dependent on whether memory function was intact or impaired, and if stimulation was applied bilaterally or unilaterally, with nearly all increase in performance seen in subjects with impaired memory receiving bilateral stimulation.
These results demonstrate that memory encoding in patients with impaired memory function can be facilitated for specific memory content, which offers a stimulation method for a future implantable neural prosthetic to improve human memory.
To evaluate the clinical implementation of pharmacotherapy recommendations for chronic obstructive pulmonary disease (COPD) based on the Global Initiative for chronic obstructive lung disease (GOLD) ...guidelines, in a longitudinal setting.
This is a sub-analysis of a prospective, non-interventional cohort study including patients with confirmed mild-to-very-severe COPD from seven pulmonary outpatient clinics in Switzerland. Follow-up visits took place annually for up to 7 years, from October 2010 until December 2016. For each visit, we evaluated the compliance of the prescribed pharmacotherapy with the concurrently valid GOLD guideline. We investigated whether step-ups or step-downs in GOLD stage or risk-group were accompanied by concordant changes in prescribed medication. Groups were compared via ANOVA.
Data of 305 patients (62±7 years, 66% men) were analysed. In 59.1% of visits, the prescribed medication conformed to the respective valid GOLD-guideline. Patients with very severe COPD were most likely to receive pharmacotherapy in compliance with guidelines. Step-ups and step-downs in risk group, requiring escalation, or de-escalation of pharmacotherapy, were noticed in 24 and 43 follow-up visits, respectively. Step-ups were adequately implemented in 4 (16.7%) and step-downs in six cases (14.0%).
The compliance of COPD-pharmacotherapy with GOLD-guidelines is suboptimal, especially in lower risk groups. The high rates of missed out treatment-adjustments suggest that the familiarity of physicians with guidelines leaves room for improvement.
As social media websites have grown in popularity, public concern about online victimization has grown as well; however, much less attention has focused on the possible beneficial effects of online ...social networks. If theory and research about in-person social networks pertain, then online social relationships may represent an important modern source of or vehicle for support. In a study of 231 undergraduates, three major findings emerged: (1) for people with weaker in-person social support, social media sites provide a source of social support that is less redundant of the social support they receive in person; (2) in ways that were not redundant of each other, both online and in-person social support were associated with lower levels of depression-related thoughts and feelings, and (3) the beneficial effects of online social support (like in-person social support) offset some of the adverse effects of peer victimization. The study suggests that augmenting social relations via strategic use of social media can enhance young people's social support systems in beneficial ways.
•The relation between online and in-person social support was curvilinear.•Social media was a less redundant source of social support for people with low levels of in-person social support.•Social media was a relatively redundant source for people with high levels of in-person social support.•Online and in-person social support evinced incremental advantages over and above the other.•Online and in-person social support both ameliorated the pernicious effects of peer victimization.
Objective
Based on Beck's hopelessness model (Beck, Kovacs, & Weissman, Journal of the American Medical Association, 234, 1975, 1146) and Joiner's (Why people die by suicide, 2005, Harvard University ...Press, Boston, MA) interpersonal theory of suicide, this study simultaneously examined three cognitive risk factors (hopelessness, thwarted belongingness, and perceived burdensomeness) as predictors of suicide ideation.
Method
The study focused on high school and college students (ns = 192 and 142, respectively), assessed twice 4 months apart.
Results
When hopelessness, perceived burdensomeness, and thwarted belongingness were examined separately, each cognitive risk factor predicted future suicide ideation in both groups. When the three cognitions were tested simultaneously, none emerged as uniquely predictive of suicide ideation. A longitudinal, latent variable model suggested that a common factor underlying all three types of cognition significantly predicted suicide ideation. Furthermore, thwarted belongingness predicted both hopelessness and perceived burdensomeness over time.
Conclusions
Results suggest ways that aspects of Beck's and Joiner's theories complement each other and could be combined to yield a more comprehensive understanding of cognitive factors associated with suicide ideation.
Objetivo/contexto: em democracias consolidadas, partidos políticos distribuem recursos internamente baseados numa estratégia para o próprio fortalecimento. Contudo, ainda são poucos os estudos ...dedicados a analisar o papel dos partidos políticos como intermediadores entre recursos financeiros e candidatos. Desse modo, analisamos as estratégias eleitorais dos partidos políticos com base nas formas pelas quais eles investem recursos financeiros próprios, especificamente advindos do caixa partidário, nas eleições para deputado federal no Brasil em 2014. Metodologia: testamos a hipótese sobre os recursos de origem partidária serem distribuídos a fim de privilegiar os candidatos que têm mandato representativo, a despeito da estrutura organizativa. A hipótese está baseada no traço personalista que caracteriza a dinâmica político-eleitoral no país. Conclusões: nossos dados apontam que as agremiações distribuem seus recursos com vistas ao potencial eleitoral dos indivíduos malgrado sua estrutura organizacional. Não importa quão robusto institucionalmente é um partido político, todos os recursos são concentrados em poucos candidatos. Tal estratégia revela que a estrutura organizacional dos partidos políticos brasileiros não guarda relação com a estratégia partidária durante as eleições legislativas. Originalidade: mostramos como os partidos brasileiros são sequestrados por seus parlamentares e, independentemente da força da organização, os recursos partidários acabam por reforçar a ausência de competição e democracia interna no interior dessas organizações.
A microsatellite or simple sequence repeat (SSR) consensus map of barley was constructed by joining six independent genetic maps based on the mapping populations 'Igri x Franka', 'Steptoe x Morex', ...'OWB(Rec) x OWB(Dom)', 'Lina x Canada Park', 'L94 x Vada' and 'SusPtrit x Vada'. Segregation data for microsatellite markers from different research groups including SCRI (Bmac, Bmag, EBmac, EBmag, HVGeneName, scsssr), IPK (GBM, GBMS), WUR (GBM), Virginia Polytechnic Institute (HVM), and MPI for Plant Breeding (HVGeneName), generated in above mapping populations, were used in the computer program RECORD to order the markers of the individual linkage data sets. Subsequently, a framework map was constructed for each chromosome by integrating the 496 "bridge markers" common to two or more individual maps with the help of the computer programme JoinMap 3.0. The final map was calculated by following a "neighbours" map approach. The integrated map contained 775 unique microsatellite loci, from 688 primer pairs, ranging from 93 (6H) to 132 (2H) and with an average of 111 markers per linkage group. The genomic DNA-derived SSR marker loci had a higher polymorphism information content value (average 0.61) as compared to the EST/gene-derived SSR loci (average 0.48). The consensus map spans 1,068 cM providing an average density of one SSR marker every 1.38 cM. Such a high-density consensus SSR map provides barley molecular breeding programmes with a better choice regarding the quality of markers and a higher probability of polymorphic markers in an important chromosomal interval. This map also offers the possibilities of thorough alignment for the (future) physical map and implementation in haplotype diversity studies of barley.
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