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For patients with symptomatic unilateral internal carotid artery (ICA) occlusion, impaired cerebrovascular reactivity (CVR) indicates increased stroke risk. Here, the role of collateral activation remains a matter of debate, whereas angio-anatomical collateral abundancy does not necessarily imply sufficient compensatory flow provided. We aimed to further elucidate the role of collateral activation in the presence of impaired CVR. From a prospective database, 62 patients with symptomatic unilateral ICA occlusion underwent blood oxygenation-level dependent (BOLD) fMRI CVR imaging and a transcranial Doppler (TCD) investigation for primary and secondary collateral activation. Descriptive statistic and multivariate analysis were used to evaluate the relationship between BOLD-CVR values and collateral activation. Patients with activated secondary collaterals exhibited more impaired BOLD-CVR values of the ipsilateral hemisphere (p = 0.02). Specifically, activation of leptomeningeal collaterals showed severely impaired ipsilateral hemisphere BOLD-CVR values when compared to activation of ophthalmic collaterals (0.05 ± 0.09 vs. 0.12 ± 0.04, p = 0.005). Moreover, the prediction analysis showed leptomeningeal collateral activation as a strong independent predictor for ipsilateral hemispheric BOLD-CVR. In our study, ipsilateral leptomeningeal collateral activation is the sole collateral pathway associated with severely impaired BOLD-CVR in patients with symptomatic unilateral ICA occlusion.

This article discusses an approach to monitoring optimization in telecommunication networks with packet routing. Mathematical model of data networking with accounting for monitoring traffic structure is described, optimization task is determined. Main attention is paid to model development on the basis of queueing theory in order to generation of reserve capacity in system. The main concept is that comparatively simple structure of monitoring network is imposed on physical structure of telecommunication network. The modeling is aimed at selection of optimum parameters of monitoring system, solution techniques for similar task are proposed. The obtained optimization task is sufficiently complicated, subsequent attempts should be aimed at searching for conditions which would enable introduction of some constraints in order to simplify its solution without noticeable loss of the model adequacy. This is especially important for asynchronous task of monitoring, it should be based on selection of the most acceptable type of objective function (linear or quadratic). Management system structure of terminal equipment monitoring has been developed for railway sector on the basis of SNMP V3. The system would permit to improve confidence level of data received from measuring system about electrical parameters of route cables, thus decreasing human errors upon classification of emergency situations occurring in communication networks.

The aim of the work was to determine the blood serum antiinflammatory cytokine IL-10 in chronic kidney disease (CKD) VD patients treated with continuous dialysis (CAPD) and their features in HD and PD patients.Materials and methods. The prospective openlabel study included 55 patients with CKD grade VD who were treated with hemo (HD) and peritoneal (PD) dialysis during 2015-2019. The study was conducted in two stages. At the first stage, the determination of IL-10 serum level. At the second stage, a prospective study of the dynamics of IL-10 in both HD and PD patients. Serum IL-10 level were determined by ELISA on «SunRise TouchScreen», «Vector Best» (RF). Statistical analysis was performed by using “SPSS for Windows version 11” and “MedStat”.Results. There was revealed a tendency towards a decrease in the average IL-10 values in the blood of patients with CKD VD – 23.4 (15.6; 109.4) in comparison with 97.7 (31.3; 143.2) pg/ml in healthy donors (20) (p=0.059). The average level of this antiinflammatory mediator in PD-patients is 23.4 (15.6; 70.3) – significantly lower than the norm (p=0.034), while in HD – only a downward trend – 27.3 (15.6; 117.2) pg/ml, p=0.089 in comparison with the norm. At the same time, the difference in mean serum levels of IL-10 when comparing groups of patients, depending on the modality of therapy, is insignificant (p=0.255).After treatment with efferent methods of therapy, the mean levels of IL-10 did not differ from the norm in both HD- (p=0.199) and PD-patients (p=0.100).Conclusion. Dialysis therapy in patients with CKD VD is accompanied by a decrease in serum levels of IL-10 (significant in PD patients) against the background of prolonged chronic inflammation with a decrease in the reserve capacity of the cells of the immune system producing it.

Highlights • Treatment decisions in older adults receiving radiotherapy is often difficult. • Older people with cancer are significantly under-represented in trials. • This is especially true of frailer older adults. • Personalised radiotherapy should include frailty assessment., It is widely accepted in clinical practice that chronological age is a poor predictor of treatment tolerance and outcomes in older adults with cancer. Intrinsic vulnerability is more a function of underlying frailty, rather than chronological age. Frailty is a state of increased vulnerability to stressors, such as cancer and its treatment, which can lead to adverse health outcomes for patients. Capturing this heterogeneity in reserve capacity is the cornerstone of management in geriatricmedicine, but remains poorly understood or adopted in radiation oncology. A two-step approach, using a shorter screening tool, followed by full assessment for those who need it, is the mostresourceful way of implementing frailty assessment in radiotherapy departments. It is important for radiation oncology professionals to identify frailty and to use this information in multidisciplinary decision making in order to develop a personalised radiotherapy approach for the older person. There are many ways we can effectively use this information, such as considering treatment fractionation schedules that would limit the burden of travel for those with social frailty, or reviewing the range of modalities at our disposal, which might limit toxicity in the older person at high risk of deterioration during treatment. Frailty assessment is not carried out in many radiotherapy departments presently, but there are many international models to use as exemplars as to how it may be implemented in clinical practice. There are many opportunities for further research and role development in this field at the current time.

Exercise intolerance is a principal feature of heart failure with preserved ejection fraction (HFpEF), whether or not there is evidence of congestion at rest. The degree of functional limitation observed in HFpEF is comparable to patients with advanced heart failure and reduced ejection fraction. Exercise intolerance in HFpEF is characterized by impairments in the physiological reserve capacity of multiple organ systems, but the relative cardiac and extracardiac deficits vary among individuals. Detailed measurements made during exercise are necessary to identify and rank-order the multiorgan system limitations in reserve capacity that culminate in exertional intolerance in a given person. We use a case-based approach to comprehensively review mechanisms of exercise intolerance and optimal approaches to evaluate exercise capacity in HFpEF. We also summarize recent and ongoing trials of novel devices, drugs, and behavioral interventions that aim to improve specific exercise measures such as peak oxygen uptake, 6-min walk distance, heart rate, and hemodynamic profiles in HFpEF. Evaluation during the clinically relevant physiological perturbation of exercise holds promise to improve the precision with which HFpEF is defined and therapeutically targeted.

Due to inherent uncertainty and volatility, large-scale wind power integration requires additional reserves for power balancing. However, it remains an open question as to how to quantify the required reserves corresponding to different uncertainties and penetration scales of wind power. This paper addresses this problem with an improved endogenous reserve determination method. Multiple uncertainties, including wind power outputs, load fluctuations, and generator failures, especially power flow uncertainties caused by wind power fluctuations and generator faults, are comprehensively integrated into a security and network-constrained economic dispatch (S&NCED) model to jointly schedule the generation and reserve. Affinely adjustable robust optimization (AARO) is adopted to address wind power and load uncertainties. Then the model is transformed into a two-stage (normal state optimization and fault verification) S&NCED model for iterative solving with the aid of Benders decomposition, and auxiliary constraints are designed to accelerate the convergence. Results of 6-bus and IEEE118-bus systems show that the proposed method can effectively provide a more economical and robust generation-reserve dispatch scheme and can clearly specify the reserve capacity required by wind power.

Priority directions and measures among the main branches of urban electric transport are resource saving in the subway transportation system during its operation. First of all, this problem must be solved by scientific support, that is, at the stage of designing parts and components of vehicles. One of the main tasks that are solved at the design stage is to increase the load-bearing capacity of the parts by analyzing their stress-strain state. The article is devoted to the calculation of the load capacity reserve of the longitudinal beam of the front subway trolley under the action of evenly distributed over the entire length of the load without taking into account the transverse forces. The priority of the research topic is substantiated, the purpose and tasks are formulated. Two approaches to the power calculation of the bearing capacity of the longitudinal beam are introduced: the calculation of the permissible stresses and the limit state. In both cases elastic models of beams are considered. In the case of calculation on the limit state, the mechanics of the occurrence of plastic hinges at the places of rigid fixing of the ends of the beam are first substantiated. The beam still retains its load capacity. With the further growth of the external load, the emergence of a plastic hinge is justified even in the middle of the beam with the simultaneous loss of the beam of the bearing capacity. To simulate the behavior of the beam according to its characteristics, including the stress and the degradation condition of its load capacity, the mathematical formulation of the problem of calculating the load capacity of the longitudinal beam when calculating the permissible stresses and the limit state without taking into account the transverse force. The load-bearing capacity of the longitudinal beam in the calculation of permissible stresses and the limit state is analyzed. The analysis of the obtained results allows us to judge the effectiveness of the proposed mathematical model as a whole. The obtained equations for the maximum allowable load when calculating the limit state and the allowable stresses allow us to reliably estimate the bearing capacity of the longitudinal beam in both cases. The increase in the bearing capacity of the beam in the case of calculation on the limit is three times. The conclusions about the adequacy of the analysis of the bearing capacity of the longitudinal beam bearing capacity were made. Keywords: resource saving, beam, bearing capacity, allowable stresses, limit state.

European electricity markets ensure the matching between supply and demand at all times. Due to their time-scale operations, the balancing markets are the last resources to achieve so and ensure the grid frequency. The increasing shares of non-dispatchable power capacities intensify the demand for flexibility. District heating systems (DHs) are potential sources of flexibility if interface technologies are in place like CHP or power-to-heat, together with thermal storage. This study assesses the technical potential of DHs to contribute to frequency containment reserves (FCR), automatic and manual frequency restoration reserves (aFRR and mFRR) markets. Through a review of case-studies, we gain insight and derive appropriate assumptions to estimate the potential at country and EU levels. Based on the POTEnCIA Central scenario up to 2050 — a description of the evolution of the EU energy system with the assumption of no further policies introduced beyond 2017 —, we find that the potential is highest for the provision of aFRR, followed by mFRR and FCR. Specifically, the aFRR technical potential is currently 32 GW — 4 times the aFRR contracted in 2019 in the EU — and it only slightly decreases by 2050. Overall, this study highlights the lack of data on current (and future) DHs and their variety in size and composition. A sensitivity analysis is performed by examining different scenarios for DHs deployment. This research emphasizes the large untapped potential to exploit flexibility from DHs, however, the evaluation of the actual potential shall be done on a case-by-case basis.

BACKGROUND AND PURPOSE: Arterial spin-labeling-derived CBF values may be affected by arterial transit time artefacts. Thus, our aim was to assess to what extent arterial spin-labeling–derived CBF and cerebrovascular reserve capacity values in major vascular regions are overestimated due to the arterial transit time artifacts in patients with Moyamoya disease. MATERIALS AND METHODS: Eight patients with Moyamoya disease were included before or after revascularization surgery. CBF maps were acquired using a 3D pseudocontinuous arterial spin-labeling sequence, before and 5, 15, and 25 minutes after an IV acetazolamide injection and were registered to each patient’s 3D-T1-weighted images. Vascular regions were defined by spatial normalization to a Montreal Neurological Institute–based vascular regional template. The arterial transit time artifacts were defined as voxels with high signal intensity corresponding to the right tail of the histogram for a given vascular region, with the cutoff selected by visual inspection. Arterial transit time artifact maps were created and applied as masks to exclude arterial transit time artifacts on CBF maps, to create corrected CBF maps. The cerebrovascular reserve capacity was calculated as CBF after acetazolamide injection relative to CBF at baseline for corrected and uncorrected CBF values, respectively. RESULTS: A total of 16 examinations were analyzed. Arterial transit time artifacts were present mostly in the MCA, whereas the posterior cerebral artery was generally unaffected. The largest differences between corrected and uncorrected CBF and cerebrovascular reserve capacity values, reported as patient group average ratio and percentage point difference, respectively, were 0.978 (95% CI, 0.968–0.988) and 1.8 percentage points (95% CI, 0.3–3.2 percentage points). Both were found in the left MCA, 15 and 5 minutes post-acetazolamide injection, respectively. CONCLUSIONS: Arterial transit time artifacts have negligible overestimation effects on calculated vascular region-based CBF and cerebrovascular reserve capacity values derived from single-delay 3D pseudocontinuous arterial spin-labeling.

The purpose of the study reported in this paper was to investigate the extent of anomalous entry, circulating and reserve capacity shrinkage at multi-lane roundabouts due to rainfall. Traffic flows, vehicle speeds, vehicle types and rainfall data were collected, collated and analysed. Three classes of rainfall intensity (light, moderate and heavy) were considered. Linear regression analysis was performed in which entry traffic flow was considered a function of circulating traffic flow. A correction factor was used to account for different entry angles and entry radii. Exponential regression and the model proposed in the 2010 Highway Capacity Manual were used to check the linear regression outcomes. The results showed that rainfall caused anomalous entry and circulating capacity shrinkage by 5%, 12% and 17% due to light, moderate and heavy rain, respectively, and also showed that such rainfalls would cause reserve capacity shrinkage by 3·7%, 8·5% and 12·5%, respectively. It was concluded that rainfall causes anomalous capacity shrinkage irrespective of its intensity.

The inherent complementarity of wind and solar energy resources is beneficial to smooth aggregate power and reduce ramp reserve capacity. This article proposes a progressive approach to assess the wind-solar complementarities in Shandong province, China for the preliminary planning of hybrid energy systems. Based on the NASA database, the long-term wind speed and solar irradiation data are obtained and transformed into capacity factors by virtual energy system models. Then, the local assessment that focuses on temporal characteristics is carried out to measure the complementarities in different time scales and search the optimal scale. Progressively, the space scale is extended from a local site to the whole study region and the global assessment is conducted to extract the spatial complementary characteristics. The assessment results are useful to provide the optimal temporal scale and spatial combination of wind-solar complementarity and the proposed approach can be generalised to other regions.

To cope with the uncertainty and variability of wind power, it is important for the power system to maintain adequate reserve capacity. The energy storage ability of the district heating system (DHS) provides considerable flexibility for the combined heat and power (CHP) units, and hence CHP can also participate in reserve capacity service. However, the CHP operation is restricted not only by its power condition, but also by the DHS heating condition, which brings difficulty in quantifying the CHP reserve flexibility. This paper focuses on properly assessing and utilizing the available reserve capacity of the CHP units as well as addressing the DHS heating constraints. The particularity for CHP reserve assessment is first analyzed and summarized as the component-coupling feature and the heating-dependency feature. Based on this, the regulating region method is proposed to describe the heating-restricted reserve capacity of the CHP units. Furthermore, an integrated power and heat dispatch approach is developed which utilizes the regulating region to formulate the available CHP reserve capacity. Finally, the numerical simulation is performed to demonstrate the necessity of precisely assessing the available reserve capacity of the CHP units and the benefit of utilizing this potential reserve flexibility for wind accommodation.

The stability of the longwall face and shields in thick coal seams requires a thorough understanding of shield–strata interaction, but the realistic hydraulic operations of longwall shields have been widely ignored to date. This paper reproduces the behaviour of the longwall face and shield in response to roof loading through a physical modelling study with a consideration of the basic operating principles of the shield leg cylinder. The extension and retraction of the leg cylinder and important characteristics of longwall shields are introduced. The results show that: (1) the shield vertical stiffness has a positive correlation with shield capacity, and it decreases with the extension of the hydraulic liquid inside the leg cylinder; (2) higher capacity shields develop more load in response to roof convergence, but retain an adequate reserve capacity to protect the shield from damage; (3) yielding of a modern shield represents a 10% drop in yielding pressure and produces 5–10 mm of reduction in shield height and 100–250 t of loss in support load; (4) the physical modelling study of shield–strata interaction with a consideration of leg hydraulic operation shows a step function of roof deflection. Face and roof displace at a slow rate during the initial shield loading stage but increase rapidly during the yielding events.

In moderate-seismic regions, cost-effective steel building design solutions such as the R=3 and ordinary concentrically braced frame (OCBF) systems do not consistently provide reliable life...

A growing body of research has pinpointed the consequences as well as mechanisms of phubbing. However, few studies have explored the relationship between peer phubbing and social networking site addiction. Based on the self-determination theory, the exclusion theory of anxiety, the social compensation model, and the reserve capacity model, the present study examined whether peer phubbing was positively related to social networking site addiction among undergraduates, whether social anxiety mediated the relationship, and whether this mediating process was moderated by family financial difficulty. Our theoretical model was tested using the data collected from 1,401 Chinese undergraduates (Mage = 18.83 years, standard deviation = 0.93). The participants completed anonymous questionnaires that assessed their peer phubbing, social anxiety, social networking site addiction, and family financial difficulty. The correlation analysis indicated that peer phubbing was positively associated with social networking site addiction. The testing for moderated mediation further revealed that social anxiety partially mediated the association between peer phubbing and social networking site addiction, with family financial difficulty moderating the first stage. To be specific, the indirect association between peer phubbing and social networking site addiction via social anxiety was stronger for undergraduates in high family financial difficulty. The results from this study extend research on the potential consequences of phubbing as well as highlight the significance of uncovering the underlying mechanisms.

Inadequate cerebral perfusion is a risk factor for cerebral ischemia in patients with large artery steno-occlusion. We investigated whether prefrontal oxyhemoglobin oscillation (ΔHbO

We focus on the optimal use of risk mitigation inventory (RMI) and reserve capacity to manage disruption risk in serial multi-stage supply chains where product transformation occurs at each stage. We find that under reasonable conditions it is better to hold more RMI downstream than upstream even when the upstream holding costs are lower. We also find that it is often optimal to hold more reserve capacity downstream than upstream. While in one-stage supply chains RMI and reserve capacity always behave as substitutes, it turns out that in multi-stage serial supply chains the interplay between RMI and reserve capacity is more nuanced. We find that echelon RMI and reserve capacity at each stage are substitutes. In contrast, RMI at a stage complements reserve capacity at the adjacent downstream stage.

Objective: To investigate the availability of any motor unit reserve capacity during fatiguing endurance testing in patients with spinal muscular atrophy (SMA). Methods: We recorded surface electromyography (sEMG) of various muscles of upper- and lower extremities of 70 patients with SMA types 2–4 and 19 healthy controls performing endurance shuttle tests (ESTs) of arm and legs. We quantitatively evaluated the development of fatigability and motor unit recruitment using time courses of median frequencies and amplitudes of sEMG signals. Linear mixed effect statistical models were used to evaluate group differences in median frequency and normalized amplitude at onset and its time course. Results: Normalized sEMG amplitudes at onset of upper body ESTs were significantly higher in patients compared to controls, yet submaximal when related to maximal voluntary contractions, and showed an inverse correlation to SMA phenotype. sEMG median frequencies decreased and amplitudes increased in various muscles during execution of ESTs in patients and controls. Conclusions: Decreasing median frequencies and increasing amplitudes reveal motor unit reserve capacity in individual SMA patients during ESTs at submaximal performance intensities. Significance: Preserving, if not expanding motor unit reserve capacity may present a potential therapeutic target in clinical care to reduce fatigability in individual patients with SMA.

The purpose of this paper is to investigate how a government sets precise subsidy policy to stimulate a manufacturer to reserve capacity for emergency supplies. Firstly, we develop a benchmark model where a manufacturer should determine its capacity strategy for future emergency supplies without government subsidy. We identify the thresholds for the manufacturer on reserving capactiy or not. Secondly, we put forward and compare four types of subsidy polices, including no subsidy, fixed subsidy, marginal subsidy, and hybrid subsidy. Thirdly, we study the government’s precise subsidy policies. The results show that the fixed subsidy policy is optimal if the fixed investment for capacity reserve is high but the marginal cost is low. When the fixed investment is low but the marginal cost is high, marginal subsidy policy is the optimal policy. The government should choose the hybrid subsidy policy if the fixed investment and marginal investment are both high. Numerical examples are included to illustrate the major results.

The implementation of this project can effectively solve the problem of water shortage in urban economic development, change the single water supply pattern of Nansha District of Guangzhou drawing water from shawan waterway in the lower beijiang River and Shenzhen and Dongguan drawing water from Dongjiang river, and improve the water supply safety and emergency reserve capacity.

Background Lymphatic abnormalities play a role in effusions in individuals with a Fontan circulation. Recent results using near‐infrared fluorescence imaging disclosed an increased contraction frequency of lymphatic vessels in Fontan patients compared to healthy controls. It is proposed that the elevated lymphatic pumping seen in the Fontan patients is necessary to maintain habitual interstitial fluid balance. Hyperthermia has previously been used as a tool for lymphatic stress test. By increasing fluid filtration in the capillary bed, the lymphatic workload and contraction frequency are increased accordingly. Using near‐infrared fluorescence imaging, the lymphatic functional reserve capacity in Fontan patients were explored with a lymphatic stress test. Methods Fontan patients (n = 33) were compared to a group of 15 healthy individuals of equal age, weight, and gender. The function of the superficial lymphatic vessels in the lower leg during rest and after inducing hyperthermia was investigated, using near‐infrared fluorescence imaging. Results Baseline values in the Fontan patients showed a 57% higher contraction frequency compared to the healthy controls (0.4 ± 0.3 min−1 vs. 0.3 ± 0.2 min−1, p = 0.0445). After inducing stress on the lymphatic vessels with hyperthermia the ability to increase contraction frequency was decreased in the Fontan patients compared to the controls (0.6 ± 0.5 min−1 vs. 1.2 ± 0.8 min−1, p = 0.0102). Conclusions Fontan patients had a higher lymphatic contraction frequency during normal circumstances. In the Fontan patients, the hyperthermia response is dampened indicating that the functional lymphatic reserve capacity is depressed. This diminished reserve capacity could be part of the explanation as to why some Fontan patients develop late‐onset lymphatic complications., We report, for the first time, that the functional lymphatic reserve capacity is depressed in patients with a Fontan circulation. Using Near‐Infrared Fluorescence imaging to asses function and morphology of the peripheral lymphatic vessels in patients with subclinical and clinical symptoms of effusions, we have introduced a new simple way to stress the lymphatic vessels to reveal lymphatic functional capacity.

In light of the latest technological achievements in wind farm control, wind power producers (WPPs) are motivated to participate in the joint day-ahead energy and reserve market (JERM) so as to obtain additional revenue by offering ancillary services. However, their expected profit is potentially affected by fast fluctuations of the available wind power in real-time, which may prevent them to deliver the capacity offered at the day-ahead stage. In order to evaluate this impact, a stochastic framework aiming at maximizing the WPP’s profit in the day-ahead JERM, based on hourly mean wind power forecasts, is firstly developed. Once the optimal bids are obtained, an empirical ex-post analysis is performed to assess the impact of actual wind speed fluctuations on the WPP’s profit. Accordingly, the resulting revenue streams from the different market floors are separately compared to their related expected values, so as to determine the losses regarding the inability of both reserve capacity procurement and activation as well as deviations from the scheduled energy. The outcomes confirm that wind speed fluctuations have a significant impact on the WPP’s ability to deliver the scheduled reserve, thus negatively impacting its actual profit.

Resting metabolic rate (RMR) declines with aging and is related to changes in health status, but how specific health impairments impact basal metabolism over time has been largely unexplored. We analyzed the association of RMR with 15 common age-related chronic diseases for up to 13 years of follow-up in a population of 997 participants to the Baltimore Longitudinal Study of Aging. At each visit, participants underwent measurements of RMR by indirect calorimetry and body composition by DEXA. Linear regression models and linear mixed effect models were used to test cross-sectional and longitudinal associations of RMR and changes in disease status. Cancer and diabetes were associated with higher RMR at baseline. Independent of covariates, prevalent COPD and cancer, as well as incident diabetes, heart failure, and CKD were associated with a steeper decline in RMR over time. Chronic diseases seem to have a two-phase association with RMR. Initially, RMR may increase because of the high cost of resiliency homeostatic mechanisms. However, as the reserve capacity becomes exhausted, a catabolic cascade becomes unavoidable, resulting in loss of total and metabolically active mass and consequent RMR decline.

In the perioperative period, hypoxemia and hyperoxia are crucial factors that require attention, because they greatly affect patient prognoses. The pulse oximeter has been the only noninvasive monitor that can be used as a reference of oxygenation in current anesthetic management; however, in recent years, a new monitoring method that uses the oxygen reserve index (ORi™) has been developed by Masimo Corp. ORi is an index that reflects the state of moderate hyperoxia (partial pressure of arterial oxygen [PaO2] between 100 and 200 mmHg) using a non-unit scale between 0.00 and 1.00. ORi monitoring performed together with percutaneous oxygen saturation (SpO2) measurements may become an important technique in the field of anesthetic management, for measuring oxygenation reserve capacity. By measuring ORi, it is possible to predict hypoxemia and to detect hyperoxia at an early stage. In this review, we summarize the method of ORi, cautions for its use, and suitable cases for its use. In the near future, the monitoring of oxygen concentrations using ORi may become increasingly common for the management of respiratory function before, after, and during surgery.

The incorporation of renewable energy sources in isolated power systems is being significantly slower than in well-connected power systems. The intermittency and uncertainty of the power output of most renewable power technologies prevent a greater usage of these technologies in isolated power systems, in which the supply security is the major concern. In this paper we formulate a stochastic unit commitment problem that allows the participation of electric vehicles in energy, reserve capacity and primary frequency response markets in order to increase the flexibility of the power system operation. We explicitly consider the uncertainty in the power demand and renewable power availability, as well as accounting for the possibilities of contingencies of generating units using a N-1 security criterion. The proposed formulation is tested on an actual isolated power system comprising 38 generating units and 8 buses.

The demand for highly structurally efficient stainless steel is limited to a certain extent by its high initial cost. Therefore, the utilisation of material to the optimum possible level is important. In achieving this, further consideration should be given to enhance the design rules where beneficial effects such as pronounced strain hardening in stainless steel should be taken into account in the design process. In addition to that, a thorough understanding of the structural behaviour of stainless steel sections is also required. However, the shear behaviour and capacity of cold-formed stainless steel lipped channel beams (LCBs) have not been thoroughly investigated previously. Therefore, experimental and detailed finite element (FE) modelling were undertaken to investigate the shear behaviour and strength of stainless steel LCBs. A comprehensive parametric study was also conducted by developing 100 FE models. From the results, the available post-buckling strength in slender stainless steel LCBs was highlighted. Furthermore, the beneficial strength increment due to the strain hardening effect of stainless steel, particularly for compact LCBs in shear, was investigated. Comparisons indicated that current EN1993-1-4 and direct strength method (DSM) shear design rules are too conservative in particularly for compact sections. Thus, existing shear design rules were modified to enhance the overall prediction accuracy for stainless steel LCBs while attention was given to capture the available inelastic reserve capacity.

Introduction: Negative demographic trends are often associated with high levels of infertility, including male. In the modern literature there are data on morphofunctional changes in various organs and tissues during inflammation of various origins, obtained in experiments on animals. At the same time, there are practically no studies on changes in the seminal glands in inflammation of different etiologies. The aim of this study is to identify the morphofunctional features of the seminal glands in the dynamics of acute infectious (staphylococcal) inflammation in rats. Materials and methods: Experimental studies were performed on 40 nonlinear male rats weighing 180-200 g. Microscopic and histochemical studies were performed on the 7th, 14th, and 28th day. Results: On the 7th day of staphylococcal inflammation, morphofunctional changes in the seminal glands were detected in rats in the form of a moderate rearrangement of the spermatogenic epithelium, which was manifested by a decrease in Sertoli cells and the number of type A light spermatogonia along with an increase in the number of type A dark spermatogonia and type B spermatogonia. The described changes were accompanied by a decrease in the metabolism of nucleoproteins in epithelial cells. On the 14th day, the morphological changes were characterized by a sharp decrease in Sertoli cells, the absence of type A light spermatogonia and an increase in the number of type A dark spermatogonia and type B spermatogonia. After 28 days, there is an increase in the number of tubules with the presence of type A light and dark spermatogonia, as well as single Sertoli cells, which indicates the restoration of the morphofunctional state of the seminal glands. Conclusions: More pronounced compensatory-adaptive processes in the seminal glands occur within a period of 28 days from the start of modeling of staphylococcal inflammation. The latter is confirmed by the appearance of various shapes and sizes of tubules with restored spermatogenic epithelium of various stages of development. The presence of type A light and dark spermatogonia indicates the reserve capacity of the seminal glands.

Nowadays, the proportion of renewable energy resources is increasing. Taiwan will install a large amount of offshore wind power capacity in the west coast in the future. To deal with the uncertainties and changes from wind generation, this work focuses on the unit commitment in Taiwan’s possible high wind penetration scenarios. This work has developed a unit commitment model, which considers hourly spinning reserve capacity that covers the uncertainty on wind power and load uncertainty as well as N-1 safety criteria.

Compensatory gomerular filtration rate (GFR) increase after kidney donation results in a GFR above 50% of the predonation value. The renal functional reserve (RFR) assessed by the renal response to dopamine infusion (RFRdopa) is considered to reflect functional reserve capacity and is thought to be a tool for living donor screening. However, it is unknown if the RFRdopapredicts long-term kidney function. Between 1984 and 2017, we prospectively measured GFR (125I-iothalamate) and RFR by dopamine infusion in 937 living kidney donors. We performed linear regression analysis of predonation RFRdopaand postdonation GFR. In donors with 5-yr follow-up after donation we assessed the association with long-term GFR. Mean donor age was 52 yr (SD 11); 52% were female. Mean predonation GFR was 114 ml/min (SD 22), GFRdopawas 124 ml/min (SD 24), resulting in an RFR of 9 ml/min (SD 10). Three months postdonation, GFR was 72 ml/min (SD 15) and GFRdopawas 75 ml/min (SD 15), indicating that donors still had RFRdopa[3 ml/min (SD 6), P < 0.001]. Predonation RFRdopawas not associated with predonation GFR [standardized (st.) β −0.009, P = 0.77] but was positively associated with GFR 3 mo after donation (st. β 0.12, P < 0.001). In the subgroup of donors with 5-yr follow-up data ( n = 383), RFRdopawas not associated with GFR at 5 yr postdonation (st. β 0.05, P = 0.35). In conclusion, RFRdopais a predictor of short-term GFR after living kidney donation but not of long-term kidney function. Therefore, measurement of the RFRdopais not a useful tool for donor screening. Studies investigating long-term renal adaptation are warranted to study the effects of living kidney donation and improve donor screening.

The objective of the study was to determine the possibilities of surgical treatment and to evaluate the criteria for selecting the resection volume of the liver in patients with Klatskin tumor.Material and methods. From 2005 to 2018, 36 patients with Klatskin tumor aged from 30 to 74 years were operated in the Department of surgery of «Russian scientific center of radiology and surgical technologies n.a. acad. A. M. Granov». Radical surgical interventions (R0) were performed in 28 (77.7 %) patients. 7 (19.5 %) patients underwent palliative surgery.Results. Selection of the resection volume of the liver and bile duct was carried out on the basis of assessment of the functional state, morphological changes in the liver and results of urgent intraoperative histological examination. As a radical intervention for IIIa, IIIb and IV types of Klatskin tumor (93.1 % of patients), extensive liver resection (left-sided or right-sided hemihepatectomy) with biliary and, in the presence of invasion into the main vessels, with vascular reconstruction was performed.Сonclusion. Timely and adequate liver resection with biliary reconstruction is a radical surgical intervention for Klatskin tumors. Selection of the resection volume of the liver, especially for type IV tumors, is determined by the morphological changes and the reserve capacity of the liver. The status of the resection edge is crucial for the selection of subsequent treatment tactics. Combination of methods of regional chemoinfusion and intraductal photodynamic therapy is necessary after non-radical intervention.

Maintenance of adequate renal function after living kidney donation is important for donor outcome. Overweight donors, in particular, may have an increased risk for end-stage kidney disease (ESKD), and young female donors have an increased preeclampsia risk. Both of these risks may be associated with low postdonation renal functional reserve (RFR). Because we previously found that higher body mass index (BMI) was associated with lower postdonation RFR, we now studied the relationship between BMI and RFR in young female donors. RFR, the rise in glomerular filtration rate (GFR) (125I-iothalamate clearance) during dopamine, was measured in female donors (25) and nonoverweight donors were compared by Studentʼs t-test; the association was subsequently explored with regression analysis. We included 105 female donors [age 41 (36–44) median(IQR)] with a BMI of 25 (22–27) kg/m2. Predonation GFR was 118 (17) ml/min [mean(SD)] rising to 128 (19) ml/min during dopamine; mean RFR was 10 (10) ml/min. Postdonation GFR was 76 (13) ml/min, rising to 80 (12); RFR was 4 (6) ml/min ( P < 0.001 vs. predonation). In overweight donors, RFR was fully lost after donation (1 ml/min vs. 10 ml/min predonation, P < 0.001), and BMI was inversely associated with RFR after donation, independent of confounders (standardized β 0.37, P = 0.02). Reduced RFR might associate with the risk of preeclampsia and ESKD in kidney donors. Prospective studies should explore whether RFR is related to preeclampsia and whether BMI reduction before conception is of benefit to overweight female kidney donors during and after pregnancy.

This research focuses on managing disruption risk in supply chains using inventory and reserve capacity under stochastic demand. While inventory can be considered as a speculative risk mitigation lever, reserve capacity can be used in a reactive fashion when a disruption occurs. We determine optimal inventory levels and reserve capacity production rates for a firm that is exposed to supply chain disruption risk. We fully characterize four main risk mitigation strategies: inventory strategy, reserve capacity strategy, mixed strategy and passive acceptance. We illustrate how the optimal risk mitigation strategy depends on product characteristics (functional versus innovative) and supply chain characteristics (agile versus efficient). This work is inspired from a risk management problem of a leading pharmaceutical company.

Background. Living kidney donor safety requires reliable long-term follow-up of renal function after donation. The current study aimed to define the precision and accuracy of post-donation estimated glomerular filtration rate (eGFR) slopes compared with measured GFR (mGFR) slopes.Methods. In 349 donors (age 51 +/- 10, 54% female), we analysed eGFR according to the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault/body surface area (CG/BSA), creatinine clearance (CrCl) and mGFR (I-125-iothalamate) changes from 3 months until 5 years post-donation.Results. Donors had a pre-donation mGFR of 116 +/- 23 mL/min, at 3 months post-donation mGFR was 73 +/- 14 mL/min and at 5 years it was 79 +/- 16 mL/min. Between 3 months and 5 years post-donation, 28% of donors had a declining mGFR (-0.82 +/- 0.79 mL/min/year), 47% were stable and 25% had an increasing mGFR. Overall, eGFR equations showed good slope estimates (bias eGFR(CKD-EPI) 0.13 +/- 2.16 mL/min/year, eGFR(MDRD) 0.19 +/- 2.10 mL/min/year, eGFR(CG/BSA) -0.08 +/- 2.06 mL/min/year, CrCl -0.12 +/- 4.75 mL/min/year), but in donors with a decreasing mGFR the slope was underestimated (bias eGFR(CKD-EPI) 1.41 +/- 2.03 mL/min/year, eGFR(MDRD) 1.51 +/- 1.96 mL/min/year, eGFR(CG/BSA) 1.20 +/- 1.87 mL/min/ year). The CrCl had a high imprecision [bias interquartile range -1.51-3.41mL/min/year].Conclusions. All eGFR equations underestimated GFR slopes in donors with a declining GFR between 3 months and 5 years post-donation. This study underlines the value of mGFR in the follow-up of donors with risk of progressive GFR loss.

Partially restrained beam-column connections can be used in the gravity load system of building structures to develop moment frame action to enhance collapse prevention for low-ductility steel lateral systems. The benefit from such reserve lateral strength and stiffness is illustrated for a low-rise building with steel braced frames designed in accordance with Canadian provisions for seismic force resisting systems of the Conventional Construction category. Preliminary results from a comprehensive cyclic test program recently completed on beam-to-column joints with bolted double web angle acting with top and seat angles are presented. The test program included 23 full-scale beam-to-column sub-assemblages subjected to combined gravity shear forces and cyclic rotational demands. Experimental observations on the deformation patterns and failure modes are presented together with representative hysteretic moment-rotation responses of bolted double web angles without and with top and seat angles.

With their proportion increasing gradually, air conditioners can be a feasible option to provide certain amount of reserve for power systems using the cycle work property. In order to calculate the reserve capacity provided by aggregated loads, the responsive time and reserve characteristic are analyzed based on the physical model for a single air conditioner. According to the simulation data, the nonlinear regression model is established between the responsive time t, reserve capacity R and the key parameter distribution. Statistical tests and error analysis proved the model precision and the credibility of load reserve.

Cerebrovascular reserve capacity (CVRC) is an important parameter for treatment decisions in chronic cerebrovascular diseases. It can be assessed by measuring the acetazolamide-induced change in regional cerebral blood flow using SPECT with 99mTc-labeled hexamethylpropyleneamine oxime (99mTc-HMPAO) or PET with 15O-water. Methods: Our database was searched for patients with moyamoya vasculopathy or atherosclerotic cerebrovascular disease who had undergone 15O-water PET after normal 99mTc-HMPAO SPECT results with respect to CVRC. 15O-water PET was analyzed visually and quantitatively. Quantitative analysis was based on parametric CVRC maps generated by voxelwise image subtraction. Results: The search identified 18 patients (43 ± 15 y, 12 moyamoya vasculopathy). PET revealed impaired CVRC in 8 patients (44%). Quantitative analysis confirmed the positive visual findings in 15O-water PET and the negative findings in 99mTc-HMPAO SPECT. Conclusion:15O-water PET enables detection of impaired CVRC in a considerable fraction of symptomatic patients with stenoocclusion and negative 99mTc-HMPAO SPECT.

Firms employing both offshore outsourcing and nearshore sourcing strategies may face supply disruption, demand uncertainty, and quality risks simultaneously. Sourcing decisions become inevitably important and complicated when both profit and the customer-service level are taken into consideration. In this paper, we model a scenario where a manufacturer who faces stochastic demand procures major modules from an overseas supplier and two local suppliers. The overseas supplier offers quality products while being susceptible to disruption risks; if the local suppliers, who are completely reliable and serve as a backup, offer products that are of inferior quality, it may result in lower market acceptance and a bad experience for the final customers. The manufacturer has to reserve capacity with backup suppliers before urgent orders are placed, when the primary source experiences a shortfall. We explicitly derive the manufacturer’s optimal order quantities and reservation quantities, which are functions of the heterogeneous suppliers’ wholesale prices, reservation prices, and other parameters. The impacts of the fill-rate constraint and customer-experience quality constraint on the manufacturer’s purchasing decisions are investigated. Interesting managerial insights on the merits of backup sourcing with capacity reservations for managing demand uncertainties and supply disruption risks are also discussed. Keywords: Backup sourcing, Supply disruption, Capacity reservation, Service-level constraint, Decision-making under risk

Introduction: Cerebrovascular reserve capacity (CVRC), an important predictor and prognostic factor for patients with moyamoya disease (MMD), can be derived by measuring cerebral blood flow (CBF) before and after administration of acetazolamide (ACZ). Commonly, a single CBF measurement is performed after ACZ injection at a time point varying between 5 to 20 minutes, whereas the dynamic temporal response using sequential CBF measurements has not been studied extensively. Furthermore, current literature reports group averaged CVRCs with high standard deviations indicating a patient-specific CVRC is spread over a wide range of values. The aim of this study was to assess the temporal dynamic response of CBF and derived CVRC during the ACZ challenge using arterial spin labeling in patients with MMD. Methods: Ten patients with MMD were included before and/or after revascularisation surgery and examined on a 3T MR scanner. CBF maps, based on 3D-pseudocontineous arterial spin labeling, were acquired before and 5, 15 and 25 minutes after an i.v. ACZ injection and registered to each patient’s 3D-T1-weighted image. A vascular territory template was spatially normalised to patient-specific space, defined by the 3D-T1-weighted image, including bilateral ACA, MCA and PCA. A post label delay of 2500 ms and large regions-of-interests were used to account for possible arterial transit time artefacts. CVRC was calculated as CBF augmentation post-ACZ injection relative to baseline. Results: A total of sixteen examinations were analysed. Average peak CBF augmentation occurred at 5 min post-ACZ injection, successively decreasing at 15 - and 25 min post-ACZ injection . CVRC followed a similar pattern. Peak CBF augmentation mostly occurred at 5 min for all vascular regions (frequency distribution 5 min: 64 %, 15 min: 23 %, 25 min: 13 %). Average ratio between CVRC calculated using 15 min CBF augmentation and CVRC using true peak CBF augmentation (5, 15 or 25 min) was 0.80 to 0.90 for all vascular regions. Conclusion: CVRC assessed using 15 min as a single post-ACZ injections time point may underestimate CVRC in average by 10 % to 20 % because of individual temporal patient response. The use of multiple post-injection time points is warranted.

Scarcity pricing is a valuable step towards the evolution of electricity markets that rely increasingly on reserves for enabling the large-scale penetration of renewable resources. A real-time market for reserve capacity is essential in the implementation of scarcity pricing, in order to enable the back-propagation of the value of reserve capacity to forward markets for energy and reserve. Such a market for real-time reserve capacity does not exist currently in Europe. Consequently, the existing design of the European balancing market creates challenges for the valuation of reserves. We argue that the implementation of a real-time market for reserve capacity can be aligned with European legislation, and we describe how scarcity pricing based on operating reserve demand curves can be integrated in such a design. We discuss the ongoing scarcity pricing debate in Belgium, and highlight various implementation challenges. © 2020 The Author(s)

As the penetration of variable renewable power generation increases in power systems around the world, system security is challenged. It is crucial to coordinate the available flexible generating resources, such as hydropower, to meet the need for system balancing. However, reserved capacity on hydropower plants should only be activated if there is sufficient energy or storage capacity to either increase or decrease production. The potential change in production will also affect all reservoirs and plants connected by the cascaded topology. These issues are largely ignored or simplified in hydropower reserve scheduling models. To properly account for the possible activation of reserved capacity, several two-stage model formulations based on stochastic and robust optimization are presented and compared in this paper. The uncertainty in net load deviations due to forecasting errors in renewable power generation is considered the source of reserve capacity activation. The case study based on a real Norwegian watercourse clearly shows the benefit of using any of the two-stage model solutions over the standard deterministic reserve procurement. A novel hybrid stochastic-robust model formulation is presented and shown to efficiently increase the robustness of the solution without notably increasing the reserve procurement cost compared to the stochastic and robust models. Open Access CC-BY

In this study, a new mathematical model is presented for the master surgical scheduling (MSS) problem at the tactical level. The capacity of the operating room for each specialty is determined in the previous level and used as an input for the tactical level. In MSS, elective surgeries are often performed in a cycle for a cycle. However, this problem considers both elective and emergency patients. The model of this problem is specifically designed to achieve this tactical plan to provide emergency care, as it provides the possibility of reserving some capacity for emergency patients. The current study, forecast emergency patients by applying an artificial neural network, and reserve capacity for them are based on the demand. Fuzzy chance-constraint programming is employed to handle the uncertainty in the model. The data of a private hospital in Iran is used to solve the problem using GAMS software. The results show that the performance of the proposed method against the solution in the hospital performed better.

Due to the increased use of variable renewable energy sources, more capacity for reserves is required. Non-generating resources such as thermostatically controlled loads (TCLs) can arbitrage energy prices and provide reserves due to their thermal energy storage capacity. The quantity of reserves depends not only on the aggregate power capacity, but also on information and communication technology, exogenous parameters, and system operator requirements. Specifically, the practical limitations origin from (i) communication constraints, (ii) ambient temperature, and (iii) the dispatch time of the activation signal. This paper explores the impact of these parameters on the amount of reserves that an aggregator of TCLs can provide to the system operator based on centralized control of a TCL population. We propose a decision support tool that can be used by aggregators to decide on maximum dispatchable reserve bids. The method can accommodate the specific control algorithm and TCL population of an aggregator and is based on offline computation. It constitutes a powerful reserve bid library to be used when optimization tools become computationally intractable due to the increased number of decentralized flexible loads. QC 20201216

The aim of this work is to simulate prices in the markets for spot and spinning reserve capacity in the Nordic region. We consider four selected seasonal weeks using a model framework for multi-market price forecasting in hydro-thermal power systems. Five different cases for reserve capacity requirements are studied: no requirements, requirements per country or price area with or without the possibility to exchange reserves by reserving transmission capacity between regions. The realized income of specific hydropower plants participating in these markets was quantified for selected time periods, based on a 2030 scenario for the European power system. The results show that for certain plants, the income from participating in the reserve capacity market contributes with up to 54 % of total income under certain conditions. Index Terms: Hydro-Thermal Scheduling, Power Market Modeling, Electricity Price Forecasting, Reserve capacity.

We read with great interest and enthusiasm the article by Van Ombergen et al. (1) published in PNAS. We would like to congratulate the authors for doing this prospective study with findings of great importance to the field of space health research, and we appreciate the opportunity to make a comment. The authors found an increased ventricular cerebrospinal fluid (CSF) volume after spaceflight in supratentorial ventricular structures (i.e., lateral and the third ventricles) and further hypothesize that the impact on the supratentorial regions is an indicator for the structural compliance and CSF reserve capacity of these ventricles acting as buffers in … [↵][1]1To whom correspondence may be addressed. Email: wostyn.peter{at}skynet.be. [1]: #xref-corresp-1-1

The electric vehicle aggregator (EVA) has been considered as an effective approach to managing the flexibility of electric vehicle (EV) charging loads. In this paper, a joint bi-level optimization model is proposed for EVAs to determine their bidding and pricing strategy. The upper level model maximizes EVA's profit from reserve provision and charging service. The reserve capacity is obtained by providing incentive payment to encourage EVs to adjust their charging loads. The lower level model represents the response of individual EV to the charging price and the incentive price adopted by EVA. The simulation results verify that the method proposed could effectively improve the benefits of both EVAs and EVs.

Current US seismic design provisions allow structures in areas of lower seismicity (e.g., the Midwest and eastern North America) to be designed with modest seismic requirements as compared ...

Reducing carbon emissions in China is critical to global low-carbon transition. Switching coal to natural gas in end-use sectors is a key mitigation strategy in China, whilst insufficient natural gas reserve capacity hinders the growth of natural gas consumption. Besides strategic reserves, peak-shaving reserves are vital to tackle seasonal demand fluctuation. Identifying an appropriate scale of natural gas reserves can significantly reduce costs, whilst current studies focus on strategic reserves. In this paper, a multi-scale method is proposed to quantify the optimal scale of natural gas reserves in China, which combines three sub-models with matched temporal-spatial resolutions tackling daily, monthly peak-shaving reserves and strategic reserves respectively. Results show that the optimal scale of natural gas reserves is 14.2 percent of annual demand, higher than the level of 5.2 percent in 2017, and lower than policy targets of 15.6 percent. Results reflect the serious shortage of reserve capacity and the need of fast expansion, whilst pointing out that a small reduction in policy targets can support natural gas growth at lower costs. The optimal scale of daily, monthly peak-shaving reserves and strategic reserves is pointed out, which is 0.6, 8 and 5.6 percent of annual demand respectively.