Analyzing Chiral Symmetry Breaking in Supersymmetric Gauge Theories

We compare gap equation predictions for the spontaneous breaking of global symmetries in supersymmetric Yang-Mills theory to nonperturbative results from holomorphic effective action techniques. In the theory without matter fields, both approaches describe the formation of a gluino condensate. With $N_f$ flavors of quark and squark fields, and with $N_f$ below a certain critical value, the coupled gap equations have a solution for quark and gluino condensate formation, corresponding to breaking of global symmetries and of supersymmetry. This appears to disagree with the newer nonperturbative techniques, but the reliability of gap equations in this context and whether the solution represents the ground state remain unclear.Comment: LaTex, 14 pages, including 1 figure in EPS format. Revised to correct gluino anomalous dimension, with minor accompanying text change

Ravens ( Corvus corax) are indifferent to the gains of conspecific recipients or human partners in experimental tasks

Although cooperative behaviours are common in animals, the cognitive processes underpinning such behaviours are very likely to differ between species. In humans, other-regarding preferences have been proposed to sustain long-term cooperation between individuals. The extent to which such psychological capacities exist in other animals is still under investigation. Five hand-reared ravens were first tested in an experiment where they could provide food to a conspecific at no cost to themselves. We offered them two behavioural options that provided identical amounts of food to the actor and where one of the two options additionally delivered a reward to a recipient. Subsequently, we made the ravens play a no-cost cooperation game with an experimenter. The experimenter had the same options as the animals and matched the ravens' choices, making the prosocial choice the more profitable option. In both conditions, ravens were indifferent to the effects of their choices and hence failed to help conspecifics and to cooperate with the experimenter. While our negative results should be interpreted with care, overall, our findings suggest that the ravens had no understanding of the consequences of their actions for a potential recipient. This study adds to several others that have used a similar set-up and have reported negative results on other-regarding preferences in animal

Development and Validation of the Short-LIMOS for the Acute Stroke Unit—A Short Version of the Lucerne ICF-Based Multidisciplinary Observation Scale

IntroductionAt hospital stroke units, the time available to assess the patient's limitations in activities and participation is limited, although being essential for discharge planning. Till date, there is no quick-to-perform instrument available that captures the patient's actual performance during daily activities from a motor, cognitive, and communication perspective within the International Classification of Functioning, Disability and Health (ICF) framework. Therefore, the aim was to develop and validate a shortened version of the Lucerne ICF-Based Multidisciplinary Observation Scale (Short-LIMOS) that observes the patient's performance across ICF-domains and is applicable in the context of an acute stroke unit.MethodsThe Short-LIMOS was developed by reducing the original 45-item LIMOS to the ten most important items using a multivariable linear regression ANOVA with data of 836 stroke patients collected during inpatient neurorehabilitation. The Short-LIMOS's reliability, validity, and responsiveness were evaluated with data of 416 stroke patients in the acute stroke unit.ResultsA significant equation [F(10,825) = 232.083] with R2 of 0.738 was found for the following ten items for the Short-LIMOS: maintaining a body position (d415), changing basic body position (d410), climbing stairs (d4551), eating (d550), dressing (d540), communicating with—receiving—written messages (reading) (d325), applying knowledge, remembering facts (d179), solving complex problems (d1751), making simple decisions (d177), and undertaking a simple task (d2100). Principal component analysis revealed a Short-LIMOS motor and a Short-LIMOS cognition/communication component. The Short-LIMOS had a high internal consistency and good test-retest reliability. A moderate construct validity was shown by the significant correlation with the Barthel Index. The Short-LIMOS had neither floor nor ceiling effects.Discussion and ConclusionThe developed Short-LIMOS was found to be reliable and valid within a population of (hyper)acute and subacute stroke patients. The added value of this multidisciplinary assessment is its comprehensiveness by capturing the patient's actual performance on the motor, cognitive, and communication domain embedded in an ICF-framework in <10 mins

Can I Discharge My Stroke Patient Home After Inpatient Neurorehabilitation? LIMOS Cut-Off Scores for Stroke Patients “Living Alone” and “Living With Family”

Background: Discharge planning of stroke patients during inpatient neurorehabilitation is often difficult since it depends both on the patient's ability to perform activities of daily living (ADL) and the social context. The aim of this study was to define ADL cut-off scores using the Lucerne ICF-based multidisciplinary observation scale (LIMOS) that allow the clinicians to decide whether stroke patients who “live alone” and “live with a family” can be discharged home or must enter a nursing home. Additionally, we investigated whether age and gender factors influence these cut-off scores. Methods: A single-center retrospective cohort study was conducted to establish cut-off discharge scores for the LIMOS. Receiver-operating-characteristics curves were calculated for both patient groups “living alone” and “living with family” to illustrate the prognostic potential of the LIMOS total score with respect to their discharge goals (home alone or nursing home; home with family or nursing home). A logistic regression model was used to determine the (age- and gender-adjusted) odds ratios of being released home if the LIMOS total score was above the cut-off. A single-center prospective cohort study was then conducted to verify the adequacy of the cut-off values for the LIMOS total score. Results: A total of 687 stroke inpatients were included in both studies. For the group “living alone” a LIMOS total score above 158 indicated good diagnostic accuracy in predicting discharge home (sensitivity 93.6%; specificity 95.4%). A LIMOS total cut-off score above 130 points was found for the group “living with family” (sensitivity 92.0%; specificity 88.6%). The LIMOS total score odds ratios, adjusted for age and gender, were 292.5 [95% CI: (52.0–1645.5)] for the group “living alone” and were 89.4 [95% CI: (32.3–247.7)] for the group “living with family.” Conclusion: Stroke survivors living alone needed a higher ADL level to return home than those living with a family. A LIMOS total score above 158 points allows a clinician to discharge a patient that lives alone, whereas a lower LIMOS score above 130 points can be sufficient in a patient that lives with a family. Neither age nor gender played a significant role

Speed up discharge planning at the acute stroke unit: A development and external validation study for the early prediction of discharge home.

Background To reduce healthcare costs, it has become increasingly important to shorten the length of stay in acute stroke units. The goal of this study was to develop and externally validate a decision tree model applicable < 48 h poststroke for discharge home from an acute stroke unit with a short length of stay, and to assess the inappropriate home discharge rate. Methods A prospective study including two samples of stroke patients admitted to an acute stroke unit. The outcome was discharge home (yes/no). A classification and regression tree analysis was performed in Sample 1. The model's performance was tested in Sample 2. Results In total, 953 patients were included. The final decision tree included the patients' activities of daily living (ADL) performance <48 h poststroke, including motor function, cognition, and communication, and had an area under the curve (AUC) of 0.84 (95% confidence interval 0.76, 0.91). External validation resulted in an AUC of 0.74 (95% confidence interval 0.72, 0.77). None of the patients discharged home were re-admitted < 2 months after discharge to a hospital or admitted to a rehabilitation center for symptoms that had needed inpatient neurorehabilitation. Conclusions The developed decision tree shows acceptable external validity in predicting discharge home in a heterogeneous sample of stroke patients, only based on the patient's actual ADL performance <48 h poststroke. Importantly, discharge was safe, i.e., no re-hospitalization was registered. The tree's application to speed up discharge planning should now be further evaluated

Development and Validation of the Short-LIMOS for the Acute Stroke Unit-A Short Version of the Lucerne ICF-Based Multidisciplinary Observation Scale.

Introduction At hospital stroke units, the time available to assess the patient's limitations in activities and participation is limited, although being essential for discharge planning. Till date, there is no quick-to-perform instrument available that captures the patient's actual performance during daily activities from a motor, cognitive, and communication perspective within the International Classification of Functioning, Disability and Health (ICF) framework. Therefore, the aim was to develop and validate a shortened version of the Lucerne ICF-Based Multidisciplinary Observation Scale (Short-LIMOS) that observes the patient's performance across ICF-domains and is applicable in the context of an acute stroke unit. Methods The Short-LIMOS was developed by reducing the original 45-item LIMOS to the ten most important items using a multivariable linear regression ANOVA with data of 836 stroke patients collected during inpatient neurorehabilitation. The Short-LIMOS's reliability, validity, and responsiveness were evaluated with data of 416 stroke patients in the acute stroke unit. Results A significant equation [F (10,825) = 232.083] with R 2 of 0.738 was found for the following ten items for the Short-LIMOS: maintaining a body position (d415), changing basic body position (d410), climbing stairs (d4551), eating (d550), dressing (d540), communicating with-receiving-written messages (reading) (d325), applying knowledge, remembering facts (d179), solving complex problems (d1751), making simple decisions (d177), and undertaking a simple task (d2100). Principal component analysis revealed a Short-LIMOS motor and a Short-LIMOS cognition/communication component. The Short-LIMOS had a high internal consistency and good test-retest reliability. A moderate construct validity was shown by the significant correlation with the Barthel Index. The Short-LIMOS had neither floor nor ceiling effects. Discussion and Conclusion The developed Short-LIMOS was found to be reliable and valid within a population of (hyper)acute and subacute stroke patients. The added value of this multidisciplinary assessment is its comprehensiveness by capturing the patient's actual performance on the motor, cognitive, and communication domain embedded in an ICF-framework in <10 mins

Patient-tailored multimodal neurorehabilitation: The Lucerne model

Neurorehabilitation is a rapidly developing subspecialty of neurology due to medical advances and growing knowledge on functional recovery from brain injury such as plasticity and regeneration in the nervous system. Furthermore, progress in modern technologies facilitate new therapeutic concepts. Patient-tailored, flexible multimodal neurorehabilitation is essential in neurological diseases due to the diversity of symptoms. In addition, rehabilitative treatment should be realized from disease onset. To fulfill these goals, the neurocenter of the Cantonal Hospital Lucerne established an uninterrupted treatment chain from the emergency stage to the social and occupational reintegration, which is described in this article with a focus on stroke, Parkinson’s disease, and multiple sclerosis patients

Clinical assessment of deficits after SAH: hasty neurosurgeons and accurate neurologists

For survivors of aneurysmal subarachnoid hemorrhage (SAH), somatic and cognitive deficits can affect long-term outcomes. We were interested in comparing the deficits identified in SAH patients, including cognitive deficits, at discharge by neurosurgeons and deficits identified by neurologists upon admission to the rehabilitation unit on the same day. The assessment of deficits might have an impact on referring patients to rehabilitation. This retrospective study included 494 SAH patients treated between 2005 and 2010. Of these, 50 patients were discharged to an affiliated rehabilitation unit. Deficits were grouped into 18 categories and summarized into three groups: major somatic, minor somatic, and cognitive deficits. Major somatic deficits were identified in 16 and 20 patients (p=0.53), minor somatic deficits in 16 and 44 (p<0.0001) patients, and cognitive deficits in 36 and 45 (p<0.04) patients by neurosurgeons and neurologists, respectively. The absolute number of deficits in daily activities identified by the neurosurgeon and neurologist were 21 and 31 major somatic deficits (p=0.2), 18 and 97 minor somatic deficits (p<0.0001), and 61 and 147 cognitive deficits (p<0.0001), respectively. Significant differences in assessment of cognitive and minor somatic deficits between neurosurgeons and neurologists exist. Based on these findings, it is evident that for the neurosurgeon, there needs to be an increased awareness of the assessment of cognitive deficits and a more routine interdisciplinary approach, including the use of neuropsychological evaluations, to ensure a better triage of patients to rehabilitation or for discharge hom

Rasch validation of a new scale to measure dependency in arm use in daily life: the Upper Limb Lucerne ICF-based Multidisciplinary Observation Scale.

INTRODUCTION About 77% of adults with stroke have upper limb impairments. Many scales are available to measure the impairment and activity level of the affected limb. However, an observational scale to assess dependency on others in upper limb performance during daily life activities instead of laboratory settings is lacking. Therefore, we developed a new 5-item Upper Limb Lucerne ICF-based Multidisciplinary Observation Scale (UL-LIMOS). As next step in the psychometric analysis, we evaluated the unidimensionality and structural validity of the UL-LIMOS with Rasch Measurement Theory and we calculated a cut-off score for independent arm use in daily life activities at discharge. METHODS This is a single-center cross-sectional study in adults with (sub) acute stroke. We applied Rasch Measurement Theory (RMT) to analyze the structural validation and unidimensionality of the UL-LIMOS. The outputs provide evidence of unidimensionality, item and person fit, overall fit, differential item functioning (DIF), principal component analysis of residuals (PCAR), person separation reliability (PSR), and residual item correlations (to identify local item dependence). Person mean location, floor and ceiling effects identify proper targeting. RESULTS We recruited 407 adults with (sub) acute stroke (median age 63 years, 157 women). All items and persons fit the Rasch model. The PSR of 0.90 indicates that clinicians and researchers can reliably use the scale for individual decision-making. There were small floor (2.70%) and ceiling (13.00%) effects. The average person mean location was 1.32 ± 2.99 logits. There was no DIF. PCAR eigenvalue was 2.46 with 49.23% explained variance. Paired t-tests revealed that 0.89% of person locations were significantly different, confirming unidimensionality. One pair of items (arm and hand use and fine hand use) showed residual item correlations. The ROC's AUC was 0.90, CI95% = [0.85-0.96] with cut-off score of ≥14/20, and high sensitivity (87%, CI95% = [81%-91%]), specificity (83%, CI95% = [77%-87%]) for independent arm use in daily living at discharge. DISCUSSION The new Rasch-based UL-LIMOS is a valid ICF-based observation performance scale at the ICF-activity level, to evaluate dependency during upper limb use in daily life in adults with stroke. Additional psychometric analyses are warranted. The UL-LIMOS would be a valuable addition to the core assessments of adults with (sub) acute stroke

Information processing in long delay memory-guided saccades: further insights from TMS

The performance of memory-guided saccades with two different delays (3s and 30s of memorisation) was studied in eight subjects. Single pulse transcranial magnetic stimulation (TMS) was applied simultaneously over the left and right dorsolateral prefrontal cortex (DLPFC) 1s after target presentation. In both delays, stimulation significantly increased the percentage of error in amplitude of memory-guided saccades. Furthermore, the interfering effect of TMS was significantly higher in the short delay compared to that of the long delay paradigm. The results are discussed in the context of a mixed model of spatial working memory control including two components: First, serial information processing with a predominant role of the DLPFC during the early period of memorisation and, second, parallel information processing, which is independent from the DLPFC, operating during longer delay