Unconventional magnetism in all-carbon nanofoam

We report production of nanostructured carbon foam by a high-repetition-rate, high-power laser ablation of glassy carbon in Ar atmosphere. A combination of characterization techniques revealed that the system contains both sp2 and sp3 bonded carbon atoms. The material is a novel form of carbon in which graphite-like sheets fill space at very low density due to strong hyperbolic curvature, as proposed for ?schwarzite?. The foam exhibits ferromagnetic-like behaviour up to 90 K, with a narrow hysteresis curve and a high saturation magnetization. Such magnetic properties are very unusual for a carbon allotrope. Detailed analysis excludes impurities as the origin of the magnetic signal. We postulate that localized unpaired spins occur because of topological and bonding defects associated with the sheet curvature, and that these spins are stabilized due to the steric protection offered by the convoluted sheets.Comment: 14 pages, including 2 tables and 7 figs. Submitted to Phys Rev B 10 September 200

Long-term change in nutritional status after severe traumatic brain injury

IntroductionIn the acute phase, patients who sustained a severe Traumatic Brain injury (TBI) (Glasgow Coma Scale under 8) frequently present malnutrition during critical care. Long-term nutritional outcome after a severe TBI has been less studied. Cognitive impairments and behavioural disorders together with hormonal disorders can lead to persisting malnutrition or over-eating and obesity. The purpose of this study was to follow the weight, the body mass index (BMI), albuminemia and hormonal dosage after a severe TBI.MethodsThis study relied on a research protocol designed to follow concurrently and prospectively endocrine disorders and cognitive disorders in a cohort of patients with severe TBI (Inspire-TC protocol). In the present work, we focused specifically on the evolution in weight, height, body mass index, albuminemia and endocrine abnormalities. These parameters were collected upon admission to the rehabilitation department, at 4 months, 12 months and 18 months when feasible for the severe TBI patients included in the Inspire-TC protocol. Albuminaemia was measured late after the TBI when patients agreed.Results10 patients were included. Initially 60% of the patients had biological malnutrition, 10% were overweight, 80% presented a normal BMI and 10% had an insufficient BMI. All patients gained weight during the monitoring with an overweight at 18 months for three patients. Along the overall monitoring, 44% of the patients had hormonal disruptions. The 3 patients with long-term overweight had frontal-temporal brain lesions. All three recovered walking. Only one had hormonal disruptions. Albuminaemia was normal for all patients who accepted to make this bioessay control.ConclusionThere is a tendency to gain weight after a severe TBI. Favorable factors include fronto-temporal injuries, and the presence of executive disorders. Endocrine perturbation and immobility can also contribute to overweight but were less frequently observed in this cohort

The child rape epidemic: Assessing the incidence at Red Cross Hospital, Cape Town, and establishing the need for a new national protocol

Introduction. There were 52 733 reported rapes in South Africa in 2003/2004, almost half of them involving children. South Africa is faced with the challenge of developing an appropriate management strategy to foster effective treatment and curtail the incidence of sexual assault. A child sexual assault protocol for the Western Cape exists, but does not address the specialised needs of the child. Objective. We aimed to ascertain the incidence of child rape seen at Red Cross War Memorial Children's Hospital, Cape Town, with emphasis on the circumstances that surround the victimisation of children. We also aimed to demonstrate the need for a new national standard protocol of specialised care for child victims' injuries. Method. A retrospective review of medical records of sexual assault victims from 2003 to 2005. Results. There were 294 patients, 254 females and 40 males. Victims ranged from 10 months to 13 years in age (mean 5.8 years). The number of cases and severity of injuries increased annually. There were 14 third-degree, 22 second-degree and 91 first-degree injuries. Seventy-nine per cent of assaults were by a perpetrator known to the victim. All but 5 perpetrators were male. Fifty-eight per cent of rapes occurred in the patient's own home or that of a friend or relative. Conclusion. The number and severity of injuries have increased yearly. This shift is consistent with the overall increase in reported sexual assaults. Policy makers must respond to this call. Finalising sexual assault policy, clinical management and evidence collection guidelines and ensuring that they are disseminated and implemented nationally must be prioritised. Educational drives targeting parents and patients with the demonstrated demographics must be established

The child rape epidemic

Introduction. There were 52 733 reported rapes in South Africa in 2003/2004, almost half of them involving children. South Africa is faced with the challenge of developing an appropriate management strategy to foster effective treatment and curtail the incidence of sexual assault. A child sexual assault protocol for the Western Cape exists, but does not address the specialised needs of the child. Objective. We aimed to ascertain the incidence of child rape seen at Red Cross War Memorial Children\'s Hospital, Cape Town, with emphasis on the circumstances that surround the victimisation of children. We also aimed to demonstrate the need for a new national standard protocol of specialised care for child victims\' injuries. Method. A retrospective review of medical records of sexual assault victims from 2003 to 2005. Results. There were 294 patients, 254 females and 40 males. Victims ranged from 10 months to 13 years in age (mean 5.8 years). The number of cases and severity of injuries increased annually. There were 14 third-degree, 22 second-degree and 91 first-degree injuries. Seventy-nine per cent of assaults were by a perpetrator known to the victim. All but 5 perpetrators were male. Fifty-eight per cent of rapes occurred in the patient\'s own home or that of a friend or relative. Conclusion. The number and severity of injuries have increased yearly. This shift is consistent with the overall increase in reported sexual assaults. Policy makers must respond to this call. Finalising sexual assault policy, clinical management and evidence collection guidelines and ensuring that they are disseminated and implemented nationally must be prioritised. Educational drives targeting parents and patients with the demonstrated demographics must be established. South African Medical Journal Vol. 97 (10) 2007: pp. 950-95

A comparison of the Nordtest and Japanese test methods for the moisture buffering performance of building materials

Two test methods, one worked out in a Nordtest project and the other available as a Japanese Industrial Standard, both developed to characterize building materials with respect to moisture buffering performance, are analyzed in detail by a numerical study on four different materials. Both test methods are based on a similar kind of dynamic loading, but the specifications of each test protocol vary. Therefore, the sensitivity of the test protocols is investigated by varying different protocol parameters. Subsequently, the practical applicability of the obtained values is investigated by confronting the values obtained for the four materials with the dynamic response of a small room with each of the materials used in turns as finishing material. Finally, the results determined according to the dynamic test protocol are compared with values calculated from steady-state material data.status: publishe

Surgical complications of bacille Calmette-Guérin (BCG) infection in HIV-infected children: Time for a change in policy?

AIM: Bacille Calmette-Guérin (BCG) immunisation is well established as part of the South African national expanded programme for immunisation (EPI). The World Health Organization (WHO) currently recommends that BCG be given to all asymptomatic infants irrespective of HIV exposure at birth but does not recommend BCG vaccination for children with symptomatic HIV infection. This approach, however, has led to HIV-infected neonates who are asymptomatic at birth, developing severe vaccine-related complications. We present a surgical case series, representative of a minority of the cases in circulation, in support of a change to the timing of BCG administration to HIV-exposed neonates. METHODS: A case series of 17 HIV-infected patients with surgical complications of BCG vaccination. RESULTS: Seventeen patients are presented. The first two illustrate disseminated systemic BCG infection, resulting in BCG infection of the lymph nodes, liver, spleen and tibia, and the second with gastrointestinal involvement causing bowel obstruction. The other 15 patients represent a series of severe ulcerating lymphadenitis secondary to BCG. CONCLUSION: The risks of BCG in HIV-infected infants are significant. Current recommendations are not satisfactory, and a change in policy is required to prevent the harmful effects of this vaccine in a high-risk group of patients. We believe that there is sufficient need to adequately stratify patients and vaccinate them according to a protocol that takes impaired immunity into consideration

Review of upper limb kinematics after cervical spinal cord injury: Implications for rehabilitation

IntroductionThe aim of this literature review is to provide a clear understanding of motor control and kinematic changes during open-chain upper limb (UL) movements after tetraplegia.MethodUsing data from MEDLINE between 1966 and August 2014, we investigated kinematic UL studies after tetraplegia.ResultsWe included fourteen control case and three series case studies with a total of 161 SCI participants and 126 healthy control participants. SCI participants efficiently perform a broad range of tasks with their UL This is achieved by effective scapulothoracic and glenohumeral compensation which provide a dynamic mechanical coupling between the shoulder and elbow joints thus palliating elbow extension despite triceps brachii paralysis. The mechanism is incomplete, however, since C5-C6 SCI individuals are forced to reduce overhead workspace to keep the elbow extended and to maintain the mechanical dynamic interaction between the shoulder and elbow. Furthermore, motion slowing is a clear kinematic characteristic, caused by:– decreased strength;– triceps brachii paralysis disrupting normal agonist-antagonist co-contraction;– accuracy requirements at movement endpoint;– grasping.Grasping requires a prolonged deceleration phase during transport to ensure hand placement with respect to the to-be-grasped object then wrist extension during grasping to elicit either whole hand or lateral grip. Contrary to the normal pattern, where grasping is prepared during the transport phase, SCI individuals transport the wrist in flexion leading to passive finger opening that did not attest a grip preparation particularly if object size is greater than maximal grip aperture. The pattern (wrist flexed then extended) indicates that reaching and grasping are performed consecutively suggesting that these two phases are independent. Elbow extension restoration causes increased elbow stiffness resulting in increased movement velocity, reduced need for glenohumeral compensation, and overall improved motor control.ConclusionRehabilitation and surgical restoration should take these kinematic characteristics into account to reinforce proximal and distal compensations allowing elbow extension and grasp using tenodesis and consequently favoring greater autonomy of individuals after SCI

The steering gaits of sperm

Sperm are highly specialized cells, which have been subject to substantial evolutionary pressure. Whereas some sperm features are highly conserved, others have undergone major modifications. Some of these variations are driven by adaptation to mating behaviours or fitness at the organismic level. Others represent alternative solutions to the same task. Sperm must find the egg for fertilization. During this task, sperm rely on long slender appendages termed flagella that serve as sensory antennas, propellers and steering rudders. The beat of the flagellum is periodic. The resulting travelling wave generates the necessary thrust for propulsion in the fluid. Recent studies reveal that, for steering, different species rely on different fundamental features of the beat wave. Here, we discuss some examples of unity and diversity across sperm from different species with a particular emphasis on the steering mechanisms. This article is part of the Theo Murphy meeting issue ‘Unity and diversity of cilia in locomotion and transport’

Analysis and design of solid-state circuits utilizing the NASA analysis computer program Annual report

Network Analysis for Systems Application Program /NASAP/ applicable in analysis and design of solid state circuit