The effect of water treatment unit processes on cyanobacterial trichome integrity.

Many toxic and/or noxious cyanobacteria appear in nature with a filamentous, stacked cell arrangement called trichomes. Although water treatment can be optimized to keep cyanobacterial cells intact and to avoid the release of toxic and/or noxious compounds, many physical and chemical stresses encountered during the treatment process may result in trichome truncation, decreasing treatment efficiency by allowing single cells or short trichomes to reach the product water. This makes it possible for harmful/noxious compounds as well as organic matter to enter the distribution system. Investigations in a pilot and three full-scale water treatment plants were carried out in order to elucidate the degree of trichome truncation across different unit processes. It was found that genera (Pseudanabaena, Planktolyngbya) with short trichomes ( < 10–12 cells per trichome), are hardly affected by the unit processes (loss of one to four cells respectively), while genera (Planktothrix, Geitlerinema, Dolichospermum) with longer trichomes (30+ cells per trichome) suffer from high degrees of truncation (up to 63, 30, and 56 cells per trichome respectively). The presence of a rigid sheath and/or mucilaginous layer appears to offer some protection from truncation. It was observed that certain unit processes alter the sensitivity or resilience of trichomes to disruption by physical stress. Some genera (Planktothrix, Geitlerinema) were sensitive to pre-oxidation, making them more susceptible to shear stress, while Dolichospermum sp. appears more robust after pre-oxidation. While the potential of toxicogenic genera breaking through into the product water is a real danger, in the current study no toxicogenic cyanobacteria were observed. This work stresses the need for plant operators to study the incoming cyanobacterial composition in the raw water in order to adjust treatment parameters and thus limit the potential of toxic/noxious compound breakthrough

A recursive process related to a partizan variation of wythoff

Wythoff queens is a classical combinatorial game related to very interesting mathematical results. An amazing one is the fact that the P-positions are given by $(\lfloor \phi n, \phi^2 n \rfloor)$ and $(\lfloor \phi^2 n, \phi n \rfloor)$ where $\phi = \frac{1 + \sqrt{5}}{2}$. In this paper, we analyze a different version where one player (Left) plays with a chess bishop and the other (Right) plays with a chess knight. The new game (call it chessfights) lacks a Beatty sequence structure in the P-positions as in wythoff queens. However, it is possible to formulate and prove some general results of a general recursive law which is a particular case of a partizan subtraction game

Endoscopic endonasal surgical anatomy through the prechiasmatic sulcus: the key window to suprachiasmatic and infrachiasmatic corridors

Background Classically, the transtuberculum and transplanum approaches have been utilized to reach the suprachiasmatic and infrachiasmatic corridors. The aim of this study was to provide a better understanding of the key endoscopic endonasal anatomy of the suprachiasmatic and infrachiasmatic corridors provided through selective removal of the prechiasmatic sulcus (SRPS).Method A SRPS was performed in 16 sides of 8 alcohol-fixed head specimens. Twenty anatomical measurements were collected on the suprachiasmatic and infrachiasmatic corridors. The transplanum and transtuberculum approaches were also performed.Results In the suprachiasmatic corridor, the SRPS exposed the anterior communicating artery (AComm) and the post-communicating segment of the anterior cerebral arteries in all the cases, while the pre-communicating segment of the anterior cerebral arteries, recurrent arteries of Heubner, and fronto-orbital arteries were visualized in 75% (12/16), 31% (5/16), and 69% (11/16) of cases, respectively. In the infrachiasmatic corridor, the ophthalmic segment of the internal carotid artery and superior hypophyseal arteries were always visible through the SRPS. The mean width and height of the prechiasmatic sulcus were 13.2 mm and 9.6 mm, respectively. The mean distances from the midpoint of the AComm to the anterior margin of the optic chiasm (OCh) was 5.3 mm. The mean width of the infrachiasmatic corridor was 12 3 mm at the level of the proximal margin of the ophthalmic segment of the internal carotid artery. The mean distances from the posterior superior limit of the pituitary stalk to the basilar tip and oculomotor nerve were 9.7 mm and 12.3 mm, respectively.Conclusions The SRPS provides access to the main neurovascular and cisternal surgical landmarks of the suprachiasmatic and infrachiasmatic corridors. This anatomical area constitutes the key part of the approach to the suprasellar area. To afford adequate surgical maneuverability, the transplanum or transtuberculum approaches are usually a necessary extension

Persistent pusher behavior after a stroke

Pusher behavior (PB) is a postural control disorder characterized by actively pushing away from the nonparetic side and resisting passive correction with a tendency to fall toward the paralyzed side.1 These patients have no awareness that their active pushing is counterproductive, which precludes the patients from standing without assistance. Several studies have already demonstrated that PB can occur in patients with lesions in both hemispheres, and PB is distinct from neglect and anosognosia.2-8 The high frequency of the association between PB and neurophysiological deficits might reflect an increased vulnerability of certain regions to stroke-induced injury rather than any direct involvement with the occurrence of PB.9,10 Traditionally, PB has only been reported in stroke patients; however, it has also been described under nonstroke conditions.8 Previous imaging studies have suggested the posterolateral thalamus as the brain structure that is typically damaged in pusher patients.4,11 Nevertheless, other cortical and subcortical areas, such as the insular cortex and post-central gyrus, have also been highlighted as structures that are potentially involved in the pathophysiology of PB.2,12-1

Endoscopic endonasal surgical anatomy of the optic canal: key anatomical relationships between the optic nerve and ophthalmic artery

Purpose A detailed understanding of the neurovascular relationships between the optic nerve (ON) and the ophthalmic artery (OA) in the optic canal (OC) is paramount for safe surgery. We focused on the neurovascular anatomy of this area from both an endoscopic endonasal and transcranial trajectories to compare the surgical exposures and perspectives offered by these different views and provide recommendations to increase the intraoperative safety. Methods Twenty sides of ten formalin-fixed, latex-injected head specimens were utilized. The surgical anatomy and anatomical relationships of the OA in relationship to the ON along their intracranial and intracanalicular segments was studied from endoscopic endonasal and transcranial perspectives. Results Three types of OA-ON relationships at the origin of the OA were identified: inferomedial (type 1, 35%), inferior (type 2, 55%), and inferolateral (type 3, 10%). The endoscopic endonasal trajectory offers an inferomedial perspective of the ON-OA neurovascular complex, in which the OA, especially when located inferomedially, is first encountered. When comparing with the transcranial view, all OA were covered by the nerve, type 1 was located below the medial third, type 2 below the middle third, and type 3 below the lateral third of the OC. The mean extension of the intracanalicular portion of both OA and ON was 8.9 mm, while the intracranial portion of the OA and ON were 9.3 mm and 12.4 mm, respectively. The OA, endoscopically, is located within the inferior half of the OC, and occupies 39%, 43%, and 42% of the OC height at its origin, mid, and end points, respectively. The mean distance between the superior margin of the OC at its origin and superior margin of the OA is 1.4 mm. Conclusions Detailed anatomical understanding of the OC, and the ON and OA at their intracranial and intracanalicular segments is paramount to safe surgery. When opening the OC dura endoscopically, our results suggest that a medial incision along the superior third of the OC with a proximal to distal direction is recommended to avoid injury of the OA

Systematic review and meta-analysis of the use of prokinetics in gastroesophageal reflux and in gastroesophageal reflux disease in Pediatrics

OBJECTIVE: To evaluate, by systematic review and meta-analysis, randomized studies comparing the prokinetics (domperidone, bromopride, metoclopramide and bethanechol) to placebo in the treatment of gastroesophagic reflux (GER) and gastroesophagic reflux disease (GERD) in children. METHODS: Bibliographic search for randomized clinical trials (Medline, EMBASE, Biological Abstracts, ISI/Web of Science, CINAHL, Lilacs e Cochrane). The primary outcome was the modification of reflux symptoms. Other outcomes were: GER-related complications, alterations in control exams, life quality, adverse events and abandon of treatment. RESULTS: The metanalysis included four studies on domperidone, two on metoclopramide, and one on bethanechol. No study of bromopride was retrieved. The risk of non-response to the treatment was significantly smaller in children that received prokinetics in comparison to placebo (RR 0.35, 95%CI 0.14-0.88). Individual therapeutic advantage regarding placebo was related to domperidone (n=126; RR 0.27; 95%CI 0.14-0.52, NNT 3; I2 0%) and bethanechol (n=44; RR 0.19; 95%CI 0.05-0.55; NNT 2), but not to metoclopramide (n=71; RR 0.63; 95%CI 0.07-5.71; I2 92.2%). CONCLUSIONS: The evidence for prokinetic use in GER and GERD in children is limited because the few studies report preliminary trials that evaluate short-term responses and show methodological limitations.OBJETIVO: Avaliar, por meio de revisão sistemática e metanálise, estudos randomizados que comparam os procinéticos domperidona, bromoprida, metoclopramida e betanecol ao placebo no tratamento do refluxo gastroesofágico (RGE) e da doença do refluxo gastroesofágico (DRGE) em crianças. MÉTODOS: BUsca bibliográfica de ensaios clínicos randomizados (Medline, EMBASE, Biological Abstracts, ISI/Web of Science, CINAHL, Lilacs e Cochrane). O desfecho primário foi eficácia na modificação dos sintomas de refluxo, conforme definição de autores das fontes primárias. Outras variáveis de interesse foram: complicações relacionadas ao RGE, alterações nos exames laboratoriais de controle, qualidade de vida, eventos adversos e abandono do tratamento. RESULTADOS: Foram incluídos quatro estudos com domperidona, dois com metoclopramida, um com betanecol. Nenhum estudo com bromoprida foi localizado. O risco de não resposta ao tratamento foi significativamente menor para os procinéticos quando comparados ao placebo (RR 0,35; IC95% 0,14-0,88). A vantagem terapêutica individual em relação ao placebo se manteve para a domperidona (n=126; RR 0,27; IC95% 0,14-0,52; NNT 3; I2 0%) e betanecol (n=44, RR 0,19, IC95% 0,05-0,55, NNT 2), mas não para metoclopramida (n=71; RR 0,63; IC95% 0,07-5,71, I2 92,2%). CONCLUSÕES: A evidência para o uso de procinéticos no RGE e na DRGE em crianças é limitada, pois os poucos estudos são ensaios preliminares de resposta em curto prazo e com limitações metodológicas.UFPel Centro de Medicina Baseada em EvidênciasHospital de Clínicas de Porto Alegre Instituto Nacional de Ciência e Tecnologia Translacional em MedicinaUFRJ Instituto de PsiquiatriaUNIFESP Departamento de PsiquiatriaUNIFESP, Depto. de PsiquiatriaSciEL