Reverse supply chain practices for construction and demolition waste in the Brazilian Amazon: a multi-stakeholder view.

Construction and demolition waste (CDW) is an environmental problem that affects all regions of the world. Particularly in the Brazilian Amazon Forest region, the volume of CDW generated almost doubled between 2007 and 2019. Indeed, despite Brazil having environmental regulations for waste management, these have been insufficient to solve the environmental problem because there is no CDW reverse supply chain (RSC) properly developed in the Amazon region. Previous studies have proposed a conceptual model of a CDW RSC but have hitherto failed to apply them against real world practice. This paper, therefore, attempts to test existing conceptual models that describe a CDW RSC against real industry practice prior to developing an applied model of a CDW RSC for the Brazilian Amazon. To modify the conceptual model for CDW RSC, qualitative data through 15 semi-structured interviews with five different types of stakeholders of the Amazonian CDW RSC were collected and analyzed using qualitative content analysis methods using NVivo software. The proposed applied model includes present and future reverse logistics (RL) practices, and strategies and tasks necessary for the implementation of a CDW RSC in the city of Belém of Pará, in the Brazilian Amazon. Findings reveal that several overlooked problems, particularly the limitations of the existing legal framework in Brazil, are not enough to promote a robust CDW RSC. This is perhaps the first study to examine CDW RSC in the Amazonian rainforest. Arguments provided in this study highlight the necessity for an Amazonian CDW RSC that must be promoted and regulated by the government. This can be addressed by the utilizing public-private partnership (PPP) for developing a CDW RSC.

Investigation of interfacial strength in nacre-mimicking tungsten heavy alloys for nuclear fusion applications.

Tungsten heavy alloys have been proposed as plasma facing material components in nuclear fusion reactors and require experimental investigation in their confirmation. For this purpose, a 90W-7Ni-3Fe alloy has been selected and microstructurally manipulated to present a multiphase brick-and-mortar structure of W-phase 'bricks' surrounded by a ductile 'mortar'. This work draws inspiration from nature to artificially imitate the extraordinary combination of strength and stiffness exhibited by mollusks and produce a nacre-mimicking metal matrix composite capable of withstanding the extremely hostile environment of the reactor interior and maintaining structural integrity. The underlying mechanisms behind this integrity have been probed through high-resolution structural and chemical characterization techniques and have revealed chemically diffuse phase boundaries exhibiting unexpected lattice coherency. These features have been attributed to an increase in the energy required for interfacial decohesion in these systems and the simultaneous expression of high strength and toughness in tungsten heavy alloys.

A new mechanism for void-cascade interaction from nondestructive depth-resolved atomic-scale measurements of ion irradiation-induced defects in Fe.

The nondestructive investigation of single vacancies and vacancy clusters in ion-irradiated samples requires a depth-resolved probe with atomic sensitivity to defects. The recent development of short-pulsed positron beams provides such a probe. Here, we combine depth-resolved Doppler broadening and positron annihilation lifetime spectroscopies to identify vacancy clusters in ion-irradiated Fe and measure their density as a function of depth. Despite large concentrations of dislocations and voids in the pristine samples, positron annihilation measurements uncovered the structure of vacancy clusters and the change in their size and density with irradiation dose. When combined with transmission electron microscopy measurements, the study demonstrates an association between the increase in the density of small vacancy clusters with irradiation and a remarkable reduction in the size of large voids. This, previously unknown, mechanism for the interaction of cascade damage with voids in ion-irradiated materials is a consequence of the high porosity of the initial microstructure.

The corticomotor projection to liminally-contractable forearm muscles in chronic spinal cord injury: a transcranial magnetic stimulation study.

STUDY DESIGN: A cross-sectional study in chronic spinal cord injury with cervical lesions (cSCI). OBJECTIVE: To determine the corticomotor projection and motor cortex organization of paralyzed forearm muscles that presented only liminal voluntary activation. SETTING: Burke Medical Research Institute, White Plains, NY, USA. METHODS: We identified ten people with chronic SCI who had a wrist flexor or extensor muscle with a motor power (MP) of 1 over 5. We recorded motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) over the primary motor cortex of the hemisphere contralateral to the target muscle. We measured resting motor threshold (RMT), corticomotor latency (LTY), MEP amplitude (AMP) and performed cortical motor mapping to determine the optimal site (OPT) and map area (AREA). Results were compared with the data from 18 controls. RESULTS: A MEP in the target muscle was observed for all cSCI cases. LTY was normal, while corticomotor excitability (as determined by RMT and AMP) was reduced in about half of the group. The OPT site of the motor maps was within control range for all cSCI cases, while AREA was reduced in three cases. CONCLUSIONS: Corticomotor conduction and cortical topography were appreciably normal despite only liminal activation of the target muscle with voluntary effort. Muscles with these characteristics may benefit from a targeted rehabilitation program even in the chronic phase after SCI.

Transcranial direct current stimulation (tDCS) and robotic practice in chronic stroke: the dimension of timing.

BACKGROUND: Combining tDCS with robotic therapy is a new and promising form of neurorehabilitation after stroke, however the effectiveness of this approach is likely to be influenced by the relative timing of the brain stimulation and the therapy. OBJECTIVE: To measure the kinematic and neurophysiological effects of delivering tDCS before, during and after a single session of robotic motor practice (wrist extension). METHODS: We used a within-subjects repeated-measurement design in 12 chronic (>6 months) stroke survivors. Twenty minutes of anodal tDCS was delivered to the affected hemisphere before, during, or after a 20-minute session of robotic practice. Sham tDCS was also applied during motor practice. Robotic motor performance and corticomotor excitability, assessed through transcranial magnetic stimulation (TMS), were evaluated pre- and post-intervention. RESULTS: Movement speed was increased after motor training (sham tDCS) by ∼20%. Movement smoothness was improved when tDCS was delivered before motor practice (∼15%). TDCS delivered during practice did not offer any benefit, whereas it reduced speed when delivered after practice (∼10%). MEPs were present in ∼50% of patients at baseline; in these subjects motor practice increased corticomotor excitability to the trained muscle. CONCLUSIONS: In a cohort of stroke survivors, motor performance kinematics improved when tDCS was delivered prior to robotic training, but not when delivered during or after training. The temporal relationship between non-invasive brain stimulation and neurorehabilitation is important in determining the efficacy and outcome of this combined therapy.

Preserved corticospinal conduction without voluntary movement after spinal cord injury.

STUDY DESIGN: Case report. OBJECTIVES: To identify preserved corticomotor connection in chronic spinal cord injury (SCI) in the absence of clinically observable movement. SETTING: Rehabilitation Hospital and Medical Research Institute, NY, USA. METHODS: The motor-evoked potential (MEP) response to transcranial magnetic stimulation (TMS) was recorded using surface electromyography from the right biceps brachii, extersor carpi radialis (ECR), flexor carpi radialis (FCR) and abductor pollicis brevis (APB) muscles in a 31-year-old male traumatic SCI chronic patient-ASIA B, injury level C5. Motor power scores were additionally obtained from a clinician blinded to the results of TMS. RESULTS: TMS could consistently elicit MEPs of normal latency, phase and amplitude, in the severely affected ECR muscle but not the similarly affected FCR muscle. The response in proximal and unaffected biceps muscle was larger than the healthy subject, whereas no response was obtained in the distal APB muscle as expected. CONCLUSION: TMS can identify residual pathways not apparent from clinical assessment alone, which may have prescriptive value for rehabilitation.

Chest radiograph reading and recording system: evaluation for tuberculosis screening in patients with advanced HIV.

SETTING: An antiretroviral treatment (ART) service in Gugulethu township, Cape Town, South Africa. OBJECTIVE: To assess the inter-observer agreement when using the chest radiographic reading and reporting system (CRRS) to detect radiographic abnormalities in patients with advanced human immunodeficiency virus (HIV) associated immunodeficiency being actively screened for tuberculosis (TB). Second, to assess the associated performance characteristics of radiology as a routine screening test for detection of culture-confirmed pulmonary TB. DESIGN: Radiographs from a study in which patients were actively screened for TB just before starting ART were independently reported by two CRRS-certified readers blinded to clinical status. RESULTS: Good kappa statistic agreements between observers were found when reporting any radiological abnormality consistent with TB among all patients (n = 203, kappa = 0.63, 95%CI 0.52-0.73) and among those with culture-confirmed TB (n = 53, kappa = 0.61, 95%CI 0.40-0.83). However, in comparison with sputum culture, the sensitivity (0.68, 95%CI 0.54-0.79) and specificity (0.53, 95%CI 0.45-0.61) of radiology in this patient group were low. CONCLUSION: This study provides evidence of the good inter-observer agreement using the CRRS standardised reporting methodology when used among patients with advanced HIV-associated immunodeficiency and a high prevalence of culture-proven pulmonary TB. The utility of radiology as a screening test for TB in this patient group, however, remains limited.

Effect of mild and moderate liver disease on the pharmacokinetics of isavuconazole after intravenous and oral administration of a single dose of the prodrug BAL8557.

Isavuconazole is a promising new antifungal drug with favorable pharmacokinetic properties and excellent activity against a number of fungi. It is administered as a water-soluble prodrug (BAL8557) that is cleaved by plasma esterases to isavuconazole, which is eliminated primarily by hepatic metabolism. The objective of this investigation was to assess the effect of alcohol-related liver disease on the pharmacokinetics of isavuconazole. Subjects were 16 healthy individuals, 16 with mild liver impairment, and 16 with moderate liver impairment who were randomized to receive a single oral or intravenous dose of BAL8557 equivalent to 100 mg isavuconazole. Blood samples were collected for 21 days following drug administration, and plasma concentrations of isavuconazole, BAL8557, and the cleavage product BAL8728 were measured using high-pressure liquid chromatography coupled with tandem mass spectrometry. Following intravenous administration, the half-life of isavuconazole increased from 123 h for healthy volunteers to 224 h and 302 h for subjects with mild and moderate liver impairment, respectively. The systemic clearance of isavuconazole following intravenous administration decreased from 2.73 liters/h for healthy subjects to 1.43 liters/h for subjects with moderate liver impairment (47.6% decrease [P < 0.05]). A similar decrease (23.5%) was observed after oral administration. These results suggest that a dose adjustment may be needed when isavuconazole is used to treat fungal infections in patients with liver disease.

Raised corticomotor excitability of M1 forearm area following anodal tDCS is sustained during robotic wrist therapy in chronic stroke.

PURPOSE: Anodal transcranial direct current stimulation (tDCS) can transiently increase corticomotor excitability of intrinsic hand muscles and improve upper limb function in patients with chronic stroke. As a preliminary study, we tested whether increased corticomotor excitability would be similarly observed in muscles acting about the wrist, and remain present during robotic training involving active wrist movements, in six chronic stroke patients with residual motor deficit. METHODS: Transcranial magnetic stimulation (TMS) generated motor evoked potentials (MEP) in the flexor carpi radialis (FCR) and provided a measure of corticomotor excitability and short-interval cortical inhibition (SICI) before and immediately after a period of tDCS (1 mA, 20 min, anode and TMS applied to the lesioned hemisphere), and robotic wrist training (1hr). RESULTS: Following tDCS, the same TMS current strength evoked an increased MEP amplitude (mean 168 +/- 22%SEM; p < 0.05), that remained increased after robot training (166 +/- 23%; p < 0.05). Conditioned MEPs were of significantly lower amplitude relative to unconditioned MEPs prior to tDCS (62 +/- 6%, p < 0.05), but not after tDCS (89 +/- 14%, p = 0.40), or robot training (91 +/- 8%, p = 0.28), suggesting that the increased corticomotor excitability is associated with reduced intracortical inhibition. CONCLUSION: The persistence of these effects after robotic motor training, indicates that a motor learning and retraining program can co-exist with tDCS-induced changes in cortical motor excitability, and supports the concept of combining brain stimulation with physical therapy to promote recovery after brain injury.

Chromonic liquid crystal formation by Edicol Sunset Yellow.

The solution and liquid crystalline phases formed by dissolution of the dye Edicol Sunset Yellow (ESY) in water have been examined using optical microscopy, multinuclear NMR (1H, 2H, 13C, 23Na), and X-ray diffraction. From the solution 1H and 13C spectra (particularly 13C), it is clear that the tautomeric form present in all these phases is the hydrazone, NH, structure, not the usually given azo, OH, form. Two chromonic mesophases occur: a nematic (N) phase at approximately 30-40 wt % and a hexagonal (M) phase at approximately 40-45 wt %. X-ray diffraction data show that the aggregates in the mesophases are single molecule stacks, with a typical spacing of approximately 3.5 angstroms, as expected for these systems. The NMR quadrupole splittings (2H2O, 23Na) are similar to those observed for surfactant lyotropic mesophases, suggesting that there are no water molecules or counter ions that are tightly bound to the ESY aggregates. An unusual feature of the X-ray diffraction pattern of the mesophases is the occurrence of diffuse off-axis reflections at approximately 6.8 angstroms. It is proposed that these arise from a head-to-tail packing of the molecules within the stacks.

Effects of experience in a dynamic environment on postural control.

BACKGROUND: Surfing is a balance-reliant, open skill performed in a dynamic environment rich in visual, somatosensory and vestibular information. OBJECTIVE: To evaluate adaptations to the postural control system by surfing experience. METHODS: Postural control was assessed in an upright bipedal stance in 60 male volunteers (21 elite surfers, 20 intermediate level surfers, and 19 controls) using various closed-stance positions. Six tasks were performed with two trials including a cognitive task, in the following order: eyes open, head in a neutral position (EO1); eyes closed, head in a neutral position (EC); eyes closed, head back (ECHB); eyes open, head in a neutral position, cognitive task 1 (EOC1); eyes open head in a neutral position, cognitive task 2 (EOC2); eyes open head in a neutral position (EO2). Dependent variables were area of 95th centile ellipse (AoE) and sway path length (SPL). RESULTS: All participants showed systematic increases in SPL and AoE in EC and ECHB trials. Expert surfers displayed significantly (p<0.05) increased SPL but not AoE when sharing attention with both concurrent mental tasks compared with controls. Controls showed a slight, non-significant change in postural control (reduced SPL and AoE) when attending to concurrent mental tasks. CONCLUSIONS: The findings indicate that standard postural sway indices are not able to elucidate whether expertise in surfing facilitates adaptations to the postural control system. However, concurrent mental task findings illustrate that systematic differences in balance abilities between expert surfers and controls may exist.

Agreement between clinical scoring systems used for the diagnosis of pediatric tuberculosis in the HIV era.

BACKGROUND: Diagnosis of childhood tuberculosis (TB) remains a challenge, especially in high human immunodeficiency virus (HIV) prevalence areas. METHODS: Retrospective study of TB cases registered at a pediatric hospital over a 1-year period in Kinshasa, Democratic Republic of Congo. Data were used to calculate scores for eight diagnostic scoring systems. Correlations between scores, agreement among scoring systems on which children are in need of treatment, and clinical presentation by HIV infection status were assessed using Spearman rank correlations, kappa statistics and bivariate analysis. RESULTS: The 42 HIV-infected children were more likely to be older, exposed to TB, have a history of TB, and present with lymphadenopathy and malnutrition, compared to the 45 non-HIV-infected children. Correlations of scores between scales unrelated in their development and agreement among scales on decision to treat were moderate to poor. One in seven children would not have received treatment according to at least one scale. CONCLUSION: The clinical presentation of TB in HIV-infected and non-infected children was quite similar, but HIV-infected children were more likely to have a prior history of TB. Correlation between clinical scoring systems was poor, with some disagreement on the decision of whom to treat, underscoring the need for improved childhood TB diagnostics.

Supraspinal inputs reduce corticomotor excitability during passive movement: evidence from a pure sensory stroke.

Corticomotor excitability is reduced during rhythmic passive movement compared to rest, but it is not known whether the mechanism is purely segmental or includes a supraspinal pathway. To determine how interruption of sensory projections at a supraspinal level affects corticomotor excitability during passive movement, we measured the amplitude of motor evoked potential (MEP) during 1 Hz cyclic index finger movements in a patient with a brainstem and thalamus lesion that resulted in a pure sensory stroke. Measurements of MEP amplitude and proprioception were made 14 and 64 days post-stroke. In the first study, when subjective position sense was reduced for the index finger, MEP amplitude was significantly increased during passive movement compared to rest (4.6+/-0.2 SEM mV vs. 4.0+/-0.2 mV; p=0.0281). However in the second study, when position sense had returned to normal, MEP amplitude was significantly reduced during movement compared to rest (6.2+/-0.3 mV vs. 6.6+/-0.1 mV; p=0.0224). These observations provide evidence that supraspinal sensory pathways are involved in reducing corticomotor excitability during rhythmic passive movement.

Endometrial cancer metastasis presenting as a grossly swollen toe.

Metastasis to the peripheral skeleton, especially in the face of low stage disease, is rare. This report describes the case of a 77-year-old lady with stage IC disease who underwent curative total abdominal hysterectomy and bilateral salpingo-oopherectomy 2 years prior to presenting with a painless gigantism of her fourth toe. A histologic diagnosis of dedifferentiated endometrial metastasis with sarcomatous differentiation was made following amputation of the toe. Osseous metastasis to bone is discussed in the context of endometrial carcinoma and the literature reviewed. This paper reports the first case of endometrial carcinoma metastasis presenting as gross swelling of a toe.

Effects of sustained post-traumatic shock and initial fluid resuscitation on extravascular lung water content and pulmonary vascular pressures in a porcine model of shock.

BACKGROUND: The temporal evolution of lung injury following post-traumatic shock is poorly understood. In the present study we have tested the hypothesis that manifestations of pulmonary vascular dysfunction may be demonstrable within the first hour after the onset of shock. METHODS: Twenty-nine anaesthetized pigs (mean weight 27.4 kg; (SD) 3.2) were randomly allocated to three groups: control (C, n=9), shock resuscitated with either NaCl 0.9% (S, n=10), or 4% gelatine (G, n=10). Shock was maintained for 1 h followed by fluid resuscitation with either normal saline or 4% gelatine solution. Cardiac output (CO), mean arterial pressure (MAP), mixed venous saturation (Sv(O(2))), blood lactate concentration, mean pulmonary artery pressure (MPAP), MPAP/MAP, pulmonary vascular resistance (PVR), extravascular lung water index (EVLWi), Pa(O(2))/FI(O(2)), venous admixture (Q(.)(S)/Q(.)(T)), and dynamic lung compliance (C(dyn)) were measured at baseline, beginning of shock phase, end of shock phase, and post-resuscitation. RESULTS: At the end of volume resuscitation CO was restored to control values in both shock groups. MAP remained significantly below control values (95% CI: C=70-95, S=28-52, G=45-69 mm Hg) in both shock groups. MPAP/MAP was significantly greater in both shock groups at the end of the shock phase (95% CI; C=0.15-0.24, S=0.28-0.38, G=0.32-0.42) and at the post-resuscitation phase (95% CI: C=0.12-0.30, S=0.43-0.61, G=0.32-0.49) indicating the presence of relative pulmonary hypertension. This was associated with a significant increase in PVR in Group S (F=3.9; P<0.05). There were no significant changes in Pa(O(2))/FI(O(2)), Q(.)(S)/Q(.)(T), EVLWi, or C(dyn). In a small cohort of animals a measurable increase in EVLWi (>30%) and reduction in C(dyn) (>10%) were observed. CONCLUSIONS: Pulmonary vascular injury manifesting as relative pulmonary hypertension and increased PVR may occur within the first hour after the onset of shock. These changes may not be accompanied by overt changes in oxygenation, compliance, or EVLWi. Br J Anaesth 2003; 91: 224-32

Electromagnetic characterisation of MR RF coils using the transmission-line modelling method.

The Transmission-Line Modelling (TLM) method is applied to the electromagnetic characterisation of RF coils and samples for magnetic resonance imaging MRI. Theoretical verification was performed using a simple surface coil. Experimental verification was performed using Alderman-Grant and birdcage coils constructed for use on a 7 T micro-imaging system. The modelling method enabled electromagnetic characteristics of frequency response, electromagnetic field generation, energy stored and power loss to be determined. From these parameters, coil resonant modes, B1 field profiles, voltages, currents, quality factor (Q), pi/2 pulse length, and the equivalent lumped-element circuit components of resistance, inductance and capacitance were calculated. Equations are presented that enable a comprehensive electromagnetic characterisation of the RF coil and sample to be achieved based on the results of the TLM simulations. The use of the TLM method is extended to include the design of safe arbitrary multi-nuclear pulse sequences such that the specific absorption rate (SAR) of tissue, and RF coil component safety limits are not exceeded.

Cloning and characterization of a phosphopantetheinyl transferase from Streptomyces verticillus ATCC15003, the producer of the hybrid peptide-polyketide antitumor drug bleomycin.

BACKGROUND: Phosphopantetheinyl transferases (PPTases) catalyze the posttranslational modification of carrier proteins by the covalent attachment of the 4'-phosphopantetheine (P-pant) moiety of coenzyme A to a conserved serine residue, a reaction absolutely required for the biosynthesis of natural products including fatty acids, polyketides, and nonribosomal peptides. PPTases have been classified according to their carrier protein specificity. In organisms containing multiple P-pant-requiring pathways, each pathway has been suggested to have its own PPTase activity. However, sequence analysis of the bleomycin biosynthetic gene cluster in Streptomyces verticillus ATCC15003 failed to reveal an associated PPTase gene. RESULTS: A general approach for cloning PPTase genes by PCR was developed and applied to the cloning of the svp gene from S. verticillus. The svp gene is mapped to an independent locus not clustered with any of the known NRPS or PKS clusters. The Svp protein was overproduced in Escherichia coli, purified to homogeneity, and shown to be a monomer in solution. Svp is a PPTase capable of modifying both type I and type II acyl carrier proteins (ACPs) and peptidyl carrier proteins (PCPs) from either S. verticillus or other Streptomyces species. As compared to Sfp, the only 'promiscuous' PPTase known previously, Svp displays a similar catalytic efficiency (k(cat)/K(m)) for the BlmI PCP but a 346-fold increase in catalytic efficiency for the TcmM ACP. CONCLUSIONS: PPTases have recently been re-classified on a structural basis into two subfamilies: ACPS-type and Sfp-type. The development of a PCR method for cloning Sfp-type PPTases from actinomycetes, the recognition of the Sfp-type PPTases to be associated with secondary metabolism with a relaxed carrier protein specificity, and the availability of Svp, in addition to Sfp, should facilitate future endeavors in engineered biosynthesis of peptide, polyketide, and, in particular, hybrid peptide-polyketide natural products.