Implementation of cloud computing in the German healthcare system

With the advent of artificial intelligence and Big Data - projects, the necessity for a transition from analog medicine to modern-day solutions such as cloud computing becomes unavoidable. Even though this need is now common knowledge, the process is not always easy to start. Legislative changes, for example at the level of the European Union, are helping the respective healthcare systems to take the necessary steps. This article provides an overview of how a German university hospital is dealing with European data protection laws on the integration of cloud computing into everyday clinical practice. By describing our model approach, we aim to identify opportunities and possible pitfalls to sustainably influence digitization in Germany.

Assessment of Hip Range of Motion Limitations in Cases with Low Back Pain Based on the Classified Movement System Impairment

Background

The hip joint's limitation causes lumbopelvic compensatory motions, accumulating tissue stress on the lumbar spines. It is essential and valuable to evaluate hip rotation range of motion (ROM) in different low back pain (LBP) classifications to understand them and plan the best exercise program. This study aimed to compare hip rotation ROM between subjects with and without LBP classified in movement system impairment (MSI).

Materials and Methods

In this cross-sectional study, 100 subjects with LBP were classified into different MSI subgroups (mean age of 41.66 ± 7.82 years), and 100 healthy subjects (mean age of 38.96 ± 8.84 years) participated. Passive and active hip medial and lateral rotations ROM in prone and supine positions for dominant and non-dominant lower limbs were measured.

Results

Generally, in the LBP group, minimal lateral rotation as compared to controls in movement tests measuring hip rotation ROM actively and passively, in prone and sitting positions, and for dominant and non-dominant limbs (P < 0.05). There were no significant differences among the LBP subgroups (P > 0.05).

Conclusions

Due to LBP, regardless of the MSI categories, remarkably restricted hip lateral rotation ROM.

Effect of Transfer Energy Capacitive and Resistive Therapy on Shoulder Pain, Disability, and Range of Motion in Patients With Adhesive Capsulitis: A Study Protocol for a Randomized Controlled Trial

Objective

We describe a protocol to evaluate the effectiveness of transfer energy capacitive and resistive (TECAR) therapy on shoulder passive range of motion, shoulder pain, and disability index in patients with adhesive capsulitis.

Methods

This study will be a double-blinded randomized clinical trial with a 1-month follow-up. For the purpose of this research, 30 patients with a 3-month history of shoulder pain and disability diagnosed as adhesive capsulitis will be selected and then randomized into 2 groups, including conventional physiotherapy consisting of electrophysical modalities and therapeutic exercises, which will be given to the control group. In the intervention group, after conventional physiotherapy, 10 minutes of TECAR therapy in resistive mode will be applied on both the anterior and inferior aspects of the shoulder joint. Outcome measures will be related to shoulder passive range of abduction, flexion, and external rotation that will be measured using a digital inclinometer, as well as shoulder pain and disability index that will be assessed by the validated questionnaire. Assessment will be done at baseline, 1 day after the intervention, and by passing 1 month.

Results

The statistical analysis will describe within-group and between-group comparisons; the findings will be illustrated in tables and charts.

Conclusion

Given the reason that the effectiveness of TECAR therapy has not been widely evaluated in adhesive capsulitis, the findings of this pilot study would provide baseline information on the effectiveness and complications of this treatment method and possibly propose a more appropriate protocol for patients with adhesive capsulitis.

Neuromuscular Electrical Stimulation in Conjunction with Conventional Swallowing Therapy in the Treatment of Dysphagia Caused by Multiple Sclerosis: A Single-Case Experimental Design

INTRODUCTION

Dysphagia as a consequence of multiple sclerosis (MS) puts individuals at higher risk of dehydration, malnutrition, and aspiration pneumonia. This study intended to investigate the effects of a combined program of neuromuscular electrical stimulation (NMES) and conventional swallowing therapy to improve swallow safety and efficiency, oral intake, and physical, emotional, and functional impacts of dysphagia in people with dysphagia and MS.

METHODS

In this single-case experimental study with ABA design, two participants with dysphagia caused by MS underwent 12 sessions therapy during 6 weeks following a baseline of 4 evaluation sessions. They were evaluated 4 more times in the follow-up phase after therapy sessions. Scores of Mann Assessment of Swallowing Ability (MASA), DYsphagia in MUltiple Sclerosis (DYMUS), and timed test of swallowing capacity were obtained at baseline, during treatment, and in the follow-up phases. The Dysphagia Outcome and Severity Scale (DOSS) based on videofluoroscopic swallow studies, Persian-Dysphagia Handicap Index (Persian-DHI), and Functional Oral Intake Scale (FOIS) were also completed before and after treatment. Visual analysis and percentage of nonoverlapping data were calculated.

RESULTS

MASA, DYMUS, FOIS, and DHI scores indicated significant improvement in both participants. Although the scores of the timed test of swallowing capacity in participant 1 (B.N.) and DOSS in participant 2 (M.A.) showed no changes, considerable improvements including reducing the amount of residue and the number of swallows required to clear bolus were seen in the posttreatment videofluoroscopic records of both participants.

CONCLUSION

NMES in conjunction with conventional dysphagia therapy based on motor learning principles could improve the swallowing function and decrease disabling effects of dysphagia on different aspects of life in participants with dysphagia caused by MS.

Comparison of immediate and delayed effects of superficial and deep dry needling in patients with upper trapezius myofascial trigger points

BACKGROUND

Dry needling is one of the most common treatments for this condition. In this study the immediate and delayed effects of superficial dry needling (SDN) and deep dry needling (DDN) on upper trapezius muscle function and patients' pain and disability was evaluated.

METHODS

In this quasi-experimental study, 47 women with active MTrPs were randomly divided into SDN and DDN groups and received one session treatment. Pain and disability were assessed before and one week after intervention with visual analogue scale (VAS) and neck disability index (NDI) questionnaire. Muscle activity was assessed by surface electromyography (sEMG) before, immediately and one week after intervention.

RESULTS

Both groups showed significant decrease in VAS (p < 0.001) and NDI (p < 0.001) after one week, however no significant difference were found between the groups (p > 0.05). A significant increase in sEMG activity was observed only in DDN group after one week (p < 0.007), but there were no significant differences in sEMG activity in SDN group after intervention and between the two groups (p > 0.05).

CONCLUSION

Both SDN and DDN could be effective in reducing pain and disability in patients with active MTrPs of upper trapezius muscle. Regarding muscle function DDN seems to be more effective. So that based on evaluation of the therapist in some cases with not significant muscle dysfunction SDN as a gentle and less invasive method could be used but for long term effectiveness and in those with significant muscle dysfunction DDN could be used.

The effects of intrinsic foot muscles strengthening exercises on foot kinetic parameters in pronated foot subjects during forward jump landing

Background

Pronated foot is one of the most important factors that may lead to musculoskeletal injuries of the lower extremities. Among all treatments for this disorder, intrinsic foot muscles strengthening exercises (IFMSE) have an important role in management of the individuals with pronated foot. Although the effect of the IFMSE is well accepted in this population; however, their impacts on foot kinetic are yet to be clarified. The present study aims to identify the effects of the IFMSE on foot kinetic parameters in pronated foot individuals during forward jump landing.

Materials and Methods

In this quasi-experimental study, 20 asymptomatic male and female subjects (mean age of 22.65 ± 2.51 years) with pronated foot structures were selected by using a simple non-random sampling method. The ground reaction force (GRF), rate of loading (ROL), and the resultant vector of time to stabilization (RVTTS) were examined during a forward jump landing task by using a force plate before and after six weeks of the IFMSE.

Result

The findings showed that the following parameters were not significantly change before and after of the IFMSE: GRF (1.97 ± 0.49 vs. 2.03 ± 0.54, P =0.667), ROL (.09 ±0.12 vs. 08 ±.12, P =.632), and RVTTS (2836.60 ± 1144.62 vs. 2644.35 ± 704.71, P =.479).

Conclusion

In the pronated feet subjects, the IFMSE alone was not capable of changing the kinetic parameters of the foot, or the duration of using these exercises. In this study, six weeks may not be enough to make changes the foot kinetic parameters and therefore these exercises should be used for a longer period of time.

Effects of Dry Needling on Pain in Patients with Knee Osteoarthritis: A Preliminary Study

Background

Osteoarthritis is one of the most common rheumatological diseases and is also considered as one of the causes of myofascial trigger points (MtrPs). Dry needling (DN) is one of the methods used for the treatment of the MtrPs. The aim of the current study was to investigate the effects of DN on pain in participants with knee osteoarthritis (KOA).

Materials and Methods

In this before and after preliminary clinical trial study, patients with mild to moderate KOA were enrolled. In one session, after determining the location of trigger points in quadriceps and gastrocnemius muscles, the patients underwent DN. The pain was evaluated at baseline, by passing 4 days and 1 month from the intervention using the Visual Analog Scale (VAS).

Results

Sixteen patients with a mean age of 56.5 (4.53) years old have completed the study and follow-up period. According to the ANOVA analysis, VAS values indicated a significant decrease in pain score at the 4^th and 1 month after the intervention compared to baseline (P < 0.001). There was no significant difference between VAS at the 4^th day of intervention and also 1 month later of intervention (P = 0.087).

Conclusion

The application of one session DN can lead to improvement in pain intensity in participants with mild to moderate KOA.

Dual-template rectangular nanotube molecularly imprinted polypyrrole for label-free impedimetric sensing of AFP and CEA as lung cancer biomarkers

A high-performance sensing layer based on dual-template molecularly imprinted polymer (DMIP) was fabricated and successfully applied for one-by-one detection of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) as lung cancer biomarkers. The plastic antibodies of AFP and CEA were created into the electropolymerized polypyrrole (PPy) on a fluorine-doped tin oxide (FTO) electrode. Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) tests were performed to pursue the formation and characterization of the sensing layer. Methyl orange (MO) increased the conductivity of PPy and induced the formation of MO doped PPy (PPy-MO) rectangular-shaped nanotubes. Using impedimetric detection, the rebinding of the template antigens was evaluated, the charge transfer resistance increased as the concentration of AFP and CEA increased. The linear dynamic ranges of 5-10⁴ and 10-10⁴ pg mL^-1 and detection limits of 1.6 and 3.3 pg mL^-1 were obtained for CEA and AFP, respectively. Given satisfactory results in the determination of AFP and CEA in the human serum samples, high sensitivity, and good stability of DMIP sensor made it a promising method for sensing of AFP and CEA in serum samples.

The role of cell surface proteins gene expression in diagnosis, prognosis, and drug resistance of colorectal cancer: In silico analysis and validation

Cell surface proteins (CSPs) are an important type of protein in different essential cell functions. This study aimed to distinguish overexpressed CSPs in colorectal cancer to investigate their biomarker, prognosis, and drug resistance potential. Raw data of three datasets including 1187 samples was downloaded then normalization and differential expression were performed. By the combination of the cancer genome atlas (TCGA) clinical data, survival analysis was carried out. Information of all CSPs was collected from cell surface protein atlas. The role of each candidate gene expression was investigated in drug resistance by CCEL and GDSC data from PharmacoGX. CRC samples including 30 tumor samples and adjacent normal were used to confirm data by RT-qPCR. Outcomes showed that 66 CSPs overexpressed in three datasets, and 146 CSPs expression associated with poor prognosis features in TCGA data that TIMP1 and QSOX2 can associate with poor patient survival independently. High-risk patients illustrated more fatality than low-risk patients based on the risk score calculated by the expression level of these genes. Receiver operating characteristic curve analysis showed that 39 CSPs as perfect biomarkers for diagnosis in CRC. Furthermore, QSOX2 and TIMP1 expression levels increased in tumor samples compared to adjacent normal samples. The Drug resistance analysis demonstrated ADAM12 and COL1A2 up-regulation among 66 overexpressed CSPs caused resistance to Venetoclax and Cyclophosphamide with a high estimate, respectively. Many CSPs are deregulated in CRC, and can be valuable candidates as biomarkers for diagnosis, prognosis, and drug resistance.

The Effectiveness of Sternocleidomastoid Muscle Dry Needling in Patients with Cervicogenic Headache

BACKGROUND

Cervicogenic headache (CGH) is a secondary headache with a cervical source that radiates pain to the head or face. Accordingly, one reason of CGH is myofascial trigger points. The purpose of this study was to investigate the effect of one session dry needling (DN) of myofascial trigger points of the sternocleidomastoid (SCM) muscle in patients with CGH.

MATERIALS AND METHODS

In this before-and-after clinical trial, 16 females aged 18-60 years with a clinical diagnosis of CGH were enrolled. All of the patients received one session DN into the myofascial trigger points of the SCM muscle. Headache index (HI), headache duration, headache frequency, and headache disability index (HDI) were assessed at 2 weeks before and 2 weeks after the intervention. This study was registered in Clinical Trials as IRCT20181109041599N1.

RESULTS

One session DN into myofascial trigger points of the SCM muscle showed a significant improvement in HI (P < 0.001). Duration and frequency of headache as well as HDI significantly reduced after intervention (P < 0.001).

CONCLUSION

One session DN into myofascial trigger points of the SCM muscle was effective on improvement of HI, headache duration, headache frequency, and HDI in patients with CGH.

The relationship between cross-sectional area of multifidus muscle and disability index in patients with chronic non-specific low back pain

BACKGROUND

Nonspecific low back pain (NSLBP) is a common problem that may have an effect on the level of functional ability. Imaging techniques indicated the degeneration of multifidus muscles in patients with low back pain. But its relationship with disability in NSLBP is unclear.

OBJECTIVE

To assess the relationship between changes in multifidus muscle morphology in MRI as paraclinical data with changes in the level of disability as clinical data in patients with CNLBP, whose MRI studies are normal. Moreover, the relationship between multifidus CSA and its thickness was determined.

DESIGN

Cross-sectional study.

METHODS

A total of 45 subjects with CNLBP participated in this study. Multifidus muscle thickness and cross-sectional area (CSA) for both sides in L4-L5 and L5-S1 levels were measured with MRI and Image J software. Level of disability was assessed with Roland-Morris disability index.

RESULTS

There was no significant relationship between multifidus muscle's CSA or thickness variations among the L4-L5 and L5-S1 levels and disability index score. Furthermore, Pearson's test showed significant positive relationship between thickness and CSA of muscles (p˂0.05).

CONCLUSION

The relationship between lumbar multifidus Thickness and disability in CNLBP with normal MRI study, is not proven in this study. Multifidus muscle thickness in L4-L5 or L5-S1 level can be representative of its CSA in patients with CNLBP and normal MRI.

The effects of passive stretching on the blood glucose levels of patients with type 2 diabetes

BACKGROUND

Type 2 diabetes is characterized by poor glycemic control due to decreased insulin sensitivity. Physical activity plays an important role in the management of diabetes and reduces blood glucose level. The aim of this study was to evaluate the effectiveness of passive stretching (PS) on the blood glucose level (BGL) of diabetic patients.

MATERIALS AND METHODS

In this randomized clinical trial, fifty patients with type 2 diabetes and mean age of 50.7 ± 4.8 years were randomly and equally allocated into control and intervention groups. Patients in the intervention and control groups underwent 20 min of passive stretching (PS) and passive movement (PM), respectively. BGL was measured before and immediately after, 20 min after and 1 h after PS/PM in the two study groups. BGL at the mentioned times was compared between and within the groups.

RESULTS

The findings showed that when compared with before the PS (195.7 ± 30.1), BGL significantly reduced (p < 0.001) immediately after (178.9 ± 29.7), 20 min after (183.2 ± 29.1), and 1 h after (187.8 ± 29.6) the PS. However, BGL after PM (immediately, 20 min and 1 h after PM) did not significantly change (p > 0.05).

CONCLUSION

The findings of this study indicated that PS has a significant effect on the reduction of the immediate BGL in type 2 diabetic patients. The trend reduced even though the effect remained for 1 h after PS. It is therefore suggested that the effectiveness of these types of activities should be evaluated over a longer duration of study.

The concentration data of heavy metals in vegetables of Guilan province, Iran

Food safety is a major problem currently facing the world and food consumption has been identified as the major pathway for human exposure to hazardous pollutants such as heavy metals. These datasets include the concentration of heavy metals like Cd, Pb, Cu, Ba, Co and Sn in selected vegetables in Guilan province and estimate daily intake of metals. The results of this dataset showed that the average concentration of heavy metals including Cd, Pb, Cu, Ba, Co and Sn in total vegetables were 0.55, 1.098, 4.095, 5.98, 0.69, and 0.2 mg/kg, respectively. The mint showed higher levels of Pb, Cu and Co contamination compared to other vegetables. The estimated daily intakes of Cd, Pb, Cu, Ba, Co and Sn for children were 0.311, 0.622, 2.320, 3.388, 0.391, 0.119 µg/day, whereas for adults were 0.182, 0.363, 1.357, 1.98, 0.228, 0.069 mg/kg, respectively. The present data highlights that both adults and children consuming vegetables ingest significant amount of these metals.

A comparison of foot kinetic parameters between pronated and normal foot structures during forward jump landing

BACKGROUND

Pronated foot is one of the most important factors that may lead to musculoskeletal injuries of the lower extremities. It is known that in a pronated foot, excessive mechanical loads are applied to the lower limb structures, which result in the altered foot biomechanics, including vertical ground reaction forces (VGRFs) and rate of loading (ROL). Therefore, the aim of this study was to determine the changes in foot kinetic parameters in the pronated compared to the normal foot structures.

METHODS

In this cross-sectional study, 15 individuals (mean age of 23.27 ± 3.28 years) with asymptomatic pronated feet and 15 normal subjects (mean age of 23.40 ± 3.11 years) were recruited from both genders by using a simple non-random sampling method. VGRF, ROL, and the resultant vector of time to stabilization (RVTTS) were evaluated during the forward jump landing task by using a force plate.

RESULTS

The findings showed that the following parameters were significantly higher in the group of pronated feet than in the normal subjects: VGRF (3.30 ± 0.17 vs. 2.81 ± 0.15, p = .042), ROL (0.10 ± 0.01 vs. 0.07 ± 0.006, p = .020), and RVTTS (2592.80 ± 141.24 vs. 2114.00 ± 154.77, p = .030).

CONCLUSION

All the measured foot kinetic parameters were higher in the pronated foot subjects than in the normal participants. An impaired movement control and greater forces imposed on the foot region of the pronated foot, compared to the normal foot individuals, were discovered indicating the former group's possible increase of susceptibility to various musculoskeletal injuries.

A comparison of lower limb muscle activation pattern using voluntary response index between pronated and normal foot structures during forward jump landing

BACKGROUND

Pronated of the foot is one of the important factors contributing to musculoskeletal problems affecting the lower extremities. It is known that in a pronated foot, excessive mechanical load is applied to the lower limb structures which may result in altered biomechanics and muscle activation patterns. The aim of this study was to determine changes in the muscle activation pattern of the lower extremities in individuals with pronated, compared to normal, feet, using the voluntary response index (VRI).

METHODS

In this cross sectional study, 15 asymptomatic pronated foot individuals (mean age 23.27 ± 3.28 years) and 15 normal subjects (mean age 23.40 ± 3.11 years) were recruited by simple non-random sampling. Electrical activities of gluteus medius (GM), vastus lateralis (VL), vastus medialis (VM), biceps femoris, semitendinosus (ST), and medial gastrocnemius (MG) muscles were recorded during a forward jump landing task. Voluntary response index (VRI) variables, included similarity index (SI) and magnitude (Mag) were also evaluated.

RESULTS

Muscle activity of VM (p < 0.001) and ST (p = 0.010) were significantly higher but VL (p = 0.039) and MG (p = 0.001) were significantly lower in pronated foot, compared to normal subjects. Similarity index was found to be different (p < 0.001) between pronated foot and healthy individuals. No significant difference was found in terms of Mag between the two groups (p = 0.576).

CONCLUSION

The altered pattern of lower limb muscle activation identified in the pronated foot during landing may be attributed to the different activation involving VL, VM, MG and ST muscles. Adaptations to the biomechanical effects, due to the pronated foot causing altered activation of VL, VM, MG, and ST muscles, results in an altered pattern of muscle activation. This change in activation pattern may harm the effectiveness of movement control processes; and might also predispose individuals with pronated feet, to injuries. It seems that an altered motor strategy with the aim of minimizing biomechanical changes, predisposes individuals to injuries. However, further large scale studies are needed to support the findings of the present study.

Ultrasonography in Diagnosis of Myofascial Pain Syndrome and Reliability of Novel Ultrasonic Indexes of Upper Trapezius Muscle

BACKGROUND

Myofascial pain syndrome (MPS) is a common non-articular musculoskeletal disorder. It is characterized by local and referred pain due to the presence of myofascial trigger points (MTrPs). MTrPs most commonly involve the upper trapezius muscle and can be visualized using ultrasound imaging. This study was designed to determine the inter-rater reliability of some new ultrasonographic indices of the upper trapezius muscle and the sensitivity and specificity of 2D ultrasound imaging in the diagnosis of MPS.

MATERIALS AND METHODS

This semi-experimental study enrolled 15 participants of both genders (mean age: 40.60 ± 5.74 years) with suspected symptoms of MPS. In the first step of the study, the sensitivity and specificity of ultrasonography for diagnosis of MPS was determined in a double blind manner. In the second step, some ultrasonographic measurements, such as muscle thickness, area of MTrPs in longitudinal view, echogenicity of MTrPs in longitudinal view, echogenicity of muscle with MTrPs in longitudinal and transverse views, and the pennation angle of the upper trapezius muscle were measured twice and their reliability was determined using the value of the mean of the two measurements.

RESULTS

The sensitivity and specificity of ultrasonographic diagnosis were 91% and 75%, respectively. The inter-rater reliability of upper trapezius muscle thickness, pennation angle, area of MTrPs, echogenicity of active MTrPs in longitudinal view, echogenicity of muscle with MTrPs in transverse view and echogenicity of muscle with MTrPs in longitudinal view were 0.91, 0.96, 0.93, 0.83, 0.93, and 0.91, respectively.

CONCLUSIONS

1. Our findings indicated that ultrasonography is a useful method for the diagnosis of MPS owing to its high sensitivity. 2. Appropriate reliability of the quantitative ultrasonographic indices of interest, especially the area of MTrPs and their echogenicity, could be useful for long-term monitoring and designing interventional studies for better management of the syndrome.

Feasibility of blind source separation methods for the denoising of dense-array EEG

High-density electroencephalographic recordings have recently been proved to bring useful information during the pre-surgical evaluation of patients suffering from drug-resistant epilepsy. However, these recordings can be particularly obscured by noise and artifacts. This paper focuses on the denoising of dense-array EEG data (e.g. 257 channels) contaminated with muscle artifacts. In this context, we compared the efficiency of several Independent Component Analysis (ICA) methods, namely SOBI, SOBIrob, PICA, InfoMax, two different implementations of FastICA, COM2, ERICA, and SIMBEC, as well as that of Canonical Correlation Analysis (CCA). We evaluated the performance using the Normalized Mean Square Error (NMSE) criterion and calculated the numerical complexity. Quantitative results obtained on realistic simulated data show that some of the ICA methods as well as CCA can properly remove muscular artifacts from dense-array EEG.

Comparison of serum levels of hepcidin and pro-hepcidin in hemodialysis patients and healthy subjects

Hepcidin prevents absorption of iron from the intestine and inhibits release of iron from macrophages and hepatocytes. For this reason, it seems that high levels of hepcidin are a predisposing factor for anemia in chronic inflammatory conditions such as chronic kidney disease and dialysis patients. This study was designed to determine the role of changes in the level of serum hepcidin in the management of hemodialysis patients. This study included 44 dialysis patients and 44 controls. The hepcidin and pro-hepcidin levels were measured by the enzyme linked immunosorbent assay method. The serum ferritin level was measured by the chemiluminescence method. The mean hepcidin level was 999.3 ± 996.7 ng/mL in the case group and 770.4 ± 815.9 ng/mL in the control group (P = 0.25). The mean pro-hepcidin level was, respectively, 186.1 ± 220.3 pg/mL and 150.87 ± 207.7 pg/mL, in the case group and control groups (P = 0.45). The mean (standard deviation) ferritin level was 816.4 ± 379.4 ng/mL in the case group and 193 ± 171.8 ng/mL in the control group (P < 0.001). In the case group, the correlation between serum ferritin and hepcidin was not significant (r = 0.6, P = 0.08). Also, there was no significant correlation between serum ferritin and pro-hepcidin levels (r = 0.6, P = 0.08). A positive correlation was seen between pro-hepcidin and hepcidin levels (r = 0.92, P < 0.01). In this study, the results showed that the serum hepcidin levels are high in dialysis patients and that there was no correlation with the serum ferritin levels.

Observation of turbulent-driven shear flow in a cylindrical laboratory plasma device

An azimuthally symmetric radially sheared plasma fluid flow is observed to spontaneously form in a cylindrical magnetized helicon plasma device with no external sources of momentum input. A turbulent momentum conservation analysis shows that this shear flow is sustained by the Reynolds stress generated by collisional drift turbulence in the device. The results provide direct experimental support for the basic theoretical picture of drift-wave-shear-flow interactions.

Asymmetrically localized Bud8p and Bud9p proteins control yeast cell polarity and development

Diploid strains of the budding yeast Saccharomyces cerevisiae change the pattern of cell division from bipolar to unipolar when switching growth from the unicellular yeast form (YF) to filamentous, pseudohyphal (PH) cells in response to nitrogen starvation. The functions of two transmembrane proteins, Bud8p and Bud9p, in regulating YF and PH cell polarity were investigated. Bud8p is highly concentrated at the distal pole of both YF and PH cells, where it directs initiation of cell division. Asymmetric localization of Bud8p is independent of the Rsr1p/Bud1p GTPase. rsr1/bud1 mutations are epistatic to bud8 mutations, placing Rsr1p/Bud1p downstream of Bud8p. In YF cells, Bud9p is also localized at the distal pole, yet deletion of BUD9 favours distal bud initiation. In PH cells, nutritional starvation for nitrogen efficiently prevents distal localization of Bud9p. Because Bud8p and Bud9p proteins associate in vivo, we propose Bud8p as a landmark for bud initiation at the distal cell pole, where Bud9p acts as inhibitor. In response to nitrogen starvation, asymmetric localization of Bud9p is averted, favouring Bud8p-mediated cell division at the distal pole.