Sink Removal Research Articles

Water-free patient care: a narrative review of the literature and discussion of the pressing need for a way forward

Florence Nightingale was the first person to recognize the link between the built environment and patient ill-health. More than 160 years later, the threat of the end of the antibiotic era looms large. The antimicrobial resistance action plan focuses on antimicrobial stewardship and developing new therapeutic agents. The risk from the built environment has been ignored, with wastewater systems identified as major sources of antimicrobial resistance within healthcare facilities. England is undertaking the largest healthcare construction programme globally. These facilities will be operating when antimicrobial resistance is predicted to be at its fiercest. Water-free patient care is a strategy for limiting dispersal of antimicrobial resistance, and preventing patient infections that need further evaluation in new hospitals. A narrative review was undertaken using the terms: waterless/water-free units; waterless/water-free care; sink reduction; sink removal; and washing without water. PubMed, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects were searched from January 2000 to February 2024 for reviews and original articles. Unit type, geographical location, reasons for a waterless/water-free approach, and outcomes were recorded. Seven papers were identified. Four involved adult intensive care units (ICUs), one involved a care of the elderly setting, and two involved neonatal ICUs. In five papers, the aim of intervention was to reduce Gram-negative infections/colonizations. One paper was a systematic review of 'washing without water' which reviewed cost-effectiveness and patient experience. All of the five papers focusing on Gram-negative bacilli reported a reduction in infections or colonizations post intervention. More studies are highlighting the risks from water and wastewater to patient safety, and the value of water-free strategies in reducing infection rates.

Increased harvested carbon of cropland in China

Crop harvested carbon (HC) is one of the most important components of the carbon cycle in cropland ecosystems, with a significant impact on the carbon budget of croplands. China is one of the most important crop producers, however, it is still unknown on the spatial and temporal variations of HC. This study collected statistical data on crop production at the province and county levels in China for all ten crop types from 1981 to 2020 and analyzed the magnitude and long-term trend of harvested crop carbon. Our results found a substantial increase of HC in cropland from 0.185 Gt C yr−1 in 1981 to 0.423 Gt C yr−1 in 2020 at a rate of 0.006 Gt C yr−1. The results also highlighted that the average annual carbon sink removal from crop harvesting in China from 1981 to 2020 was 0.32 Gt C yr−1, which was comparable to the net carbon sink of the entire terrestrial ecosystems in China. This study further generated a gridded dataset of HC from 2001 to 2019 in China by using jointly the statistical crop production and distribution maps of cropland. In addition, a model-data comparison was carried out using the dataset and results from seven state-of-the-art terrestrial ecosystem models, revealing substantial disparities in HC simulations in China compared to the dataset generated in the study. This study emphasized the increased importance of HC for estimating cropland carbon budget, and the produced dataset is expected to contribute to carbon budget estimation for cropland ecosystems and the entire China.

An intensive care unit outbreak with multi-drug-resistant Pseudomonas aeruginosa – spotlight on sinks

Pseudomonas aeruginosa and other Gram-negative bacteria have the ability to persist in moist environments in healthcare settings, but their spread from these areas can result in outbreaks of healthcare-associated infections. We report the investigation and containment of a multidrug-resistant P. aeruginosa outbreak in 3 intensive care units of a Swiss university hospital. A total of 255 patients and 276 environmental samples were screened for the multidrug-resistant P. aeruginosa outbreak strain. We describe the environmental sampling and molecular characterization of patient and environmental strains, control strategies implemented, including waterless patient care. Between March and November 2019, the outbreak affected 29 patients. Environmental sampling detected the outbreak strain in nine samples of sink siphons of three different intensive care units sharing an identical water sewage system and on one gastroscope. Three weeks after sink siphon replacement, the outbreak strain grew again in siphon-derived samples and newly-affected patients were identified. The outbreak ceased after removal of all sinks in the proximity of patients and in medication preparation areas and minimization of tap water use. Multilocus sequence typing indicated clonality (sequence type 316) in 28/29 patient isolates and all 10 environmental samples. Sink removal combined with the introduction of waterless patient care terminated the multidrug-resistant P. aeruginosa outbreak. Sinks in intensive care units might pose a risk for point source outbreaks with P. aeruginosa and other bacteria persisting in moist environments.

Impact of sink removal from intensive care unit rooms on the consumption of antibiotics and on results of Zero Resistance Project

IntroductionDue to the favourable impact of removing the sinks on isolations in bronchoaspirate samples of patients with mechanical ventilation, we now evaluate the impact on the consumption of antibiotics as well as on the results of the Zero Resistance Project (ZRP). Patients and methodsAll the patients admitted to the unit in a quasi-experimental before–after study with a pre-intervention period between 2014 and 2016 and a post-intervention period from 2016 to 2017, to evaluate antibiotic consumption in defined daily doses, and until 2018, to evaluate the ZRP indicators. The intervention was the removal of the sinks from the rooms of the ICU. We evaluated antibiotic consumption densities and their ratios, grouped as Enterobacteriaceae and non-fermenting gram-negative bacilli (NFGNB) according to their antibiograms; the absolute number of ‘antibiotic days’, ‘hospitalised days’, ‘isolation days’, and ‘multi-resistant bacteria (MRB) days’; as well as their incidence densities per 1000 hospitalised days and the ratio between the two years prior to and the two years after the intervention. ResultsPost-intervention antibiotic use was 1.61-fold (1.60–1.62) and 2.24-fold (2.10–2.37) lower for antibiotics used against Enterobacteriaceae and NFGNB, respectively. There were also reductions in the number of days of antibiotic use by 1.29-fold (1.22–1.36), number of MRB days by 1.84-fold (1.63–2.08), and number of patient isolation days by 1.51-fold (1.38–1.66). DiscussionThe results suggest that the intervention had a favourable impact on the consumption of antibiotics, as well as on the number of days on antibiotics, MRB, and isolation.

Changes in photosynthesis and chlorophyll a fluorescence in relation to leaf temperature from just before to after harvest of Vitis vinifera cv. Shiraz vines grown in outdoor conditions.

Harvesting fruit from horticultural species causes a down-regulation of photosynthesis but some species can recover after harvest. The objective of this study was to assess the hypothesis that the impact of fruit removal on the photosynthetic performance of Shiraz grapevines, in relation to CO2 concentration and leaf temperature, would contribute to a depreciation in photosynthetic assimilation. To assess this hypothesis, vines that were continuously vegetative were compared with vines that were harvested when fruit were ripe. These fruiting vines had higher rates of CO2 -limited photosynthesis at all leaf temperatures compared to vegetative vines before harvest but after, photosynthetic rates were highest in vegetative vines. There were few treatment differences in CO2 -saturated photosynthesis before harvest but after, below about 30°C, the harvested vines had higher photosynthesis than the vegetative vines. Maximum rates of ribulose 1,5 bisphosphate (RuBP) carboxylation and regeneration and responses to temperature were unaffected by differences in sink demand but after harvest, maximum rates increased, but markedly more in the vegetative vines, especially at higher temperatures. This conformed to higher photosynthetic rates in the vegetative vines. There were no sink demand effects on chlorophyll a fluorescence, consistent with the evidence that the fruit sink removal probably affected Rubisco activity and performance. The conclusion that sink removal caused a depreciation in photosynthesis was sustained but the temperature had a strong modulating effect through both stomatal and non-stomatal limitations driving the depreciation in assimilation. What was less clear was why assimilation of continuously vegetative vines increased during the harvest time when there were no apparent changes in sink demand.

Preventing infections caused by carbapenemase-producing bacteria in the intensive care unit - Think about the sink.

Outbreaks caused by carbapenemase-producing bacteria (CPB) are challenging to manage in critical care settings and can be protracted due to inadvertent and ubiquitous ecological niches within the built unit environment, such as handwashing sinks. We discuss evidence from a narrative review on transmission pathways and interventions for critical care practitioners. A literature review was undertaken using Pubmed, CINAHL and Embase and included outbreaks of CPB, and equivalent bacteria in critical care units, between 1998 and May 2020. Intervention studies targeting elements of sinks that were employed in response to outbreaks in critical care units were included (n=30). We found control measures included sink removal, use of physical barriers or design modification to protect patients from sinks, engineering controls to mitigate bacterial dispersal and administrative controls. A multi-disciplinary approach involving practitioners from critical care, infection prevention and control, engineering and other staff, should be involved in ongoing measures and in outbreak control activities. Ascertaining the optimal method to end CPB outbreaks in critical care is challenging due to the lack of prospective studies available. However, the literature suggests that sinks can and do serve as reservoirs of CPB near critically ill patients, and should be considered hazardous, especially when sub-optimally designed or used.

Grain sink removal increases stalk juice yield, sugar accumulation, and biomass in sweet sorghum [Sorghum bicolor (L.) Moench

Sweet sorghum is cultivated primarily for its sugar-rich stalks. The extent to which stalk sugar accumulation occurs is determined by several factors including the grain sink. A Genetic system exists whereby the grain sink can be eliminated to maximize sugar accumulation in the stalks. Before engaging in the development of such system, establishing the extent to which stalk sugar can be improved by removing the grain sink becomes necessary. The aim of this study was to determine the effect of eliminating the grain sink on biomass and sugar accumulation. The experiment consisted of two factors, genotype and sink load. The genotype factor consisted of 22 sweet sorghum lines of variable sugar content, and the sink factor consisted of no-grain and full-grain set. Treatments were arranged in split plot in a randomized complete block design with genotypes assigned to the main plot and the sink effect to the subplot. The study was conducted in four replications in three environments. The no-grain sink treatment was applied by manually removing the panicles prior to anthesis. Analysis of the data collected from one-meter sections of each plot at physiological maturity showed that the genotype effect was significant (P ≤ 0.01) for all traits. Elimination of the grain sink prior to anthesis significantly increased °Brix, wet and dry biomass, and total sugar by 18, 28, and 43%, respectively. These results justify further development of sorghum varieties without a grain sink to maximize sugar yield for biofuel production.

Impact of sink removal from intensive care unit rooms on the consumption of antibiotics and on results of Zero Resistance Project

IntroductionDue to the favourable impact of removing the sinks on isolations in bronchoaspirate samples of patients with mechanical ventilation, we now evaluate the impact on the consumption of antibiotics as well as on the results of the Zero Resistance Project (ZRP). Patients and methodsAll the patients admitted to the unit in a quasi-experimental before–after study with a pre-intervention period between 2014 and 2016 and a post-intervention period from 2016 to 2017, to evaluate antibiotic consumption in defined daily doses, and until 2018, to evaluate the ZRP indicators. The intervention was the removal of the sinks from the rooms of the ICU. We evaluated antibiotic consumption densities and their ratios, grouped as Enterobacteriaceae and non-fermenting gram-negative bacilli (NFGNB) according to their antibiograms; the absolute number of ‘antibiotic days’, ‘hospitalised days’, ‘isolation days’, and ‘multi-resistant bacteria (MRB) days’; as well as their incidence densities per 1000 hospitalised days and the ratio between the two years prior to and the two years after the intervention. ResultsPost-intervention antibiotic use was 1.61-fold (1.60–1.62) and 2.24-fold (2.10–2.37) lower for antibiotics used against Enterobacteriaceae and NFGNB, respectively. There were also reductions in the number of days of antibiotic use by 1.29-fold (1.22–1.36), number of MRB days by 1.84-fold (1.63–2.08), and number of patient isolation days by 1.51-fold (1.38–1.66). DiscussionThe results suggest that the intervention had a favourable impact on the consumption of antibiotics, as well as on the number of days on antibiotics, MRB, and isolation.

Sink Removal from Digital Elevation Model–A Necessary Evil for Hydrological Analysis

Sink Removal from Digital Elevation Model–A Necessary Evil for Hydrological Analysis

Changes in the temperature-dependency of the photosynthetic response to chloroplast CO2 concentrations of outdoor-grown Vitis vinifera cv. Shiraz vines with a mid-season crop removal

Removing fruit from horticultural trees and vines is a common practice in source-sink studies. What effect removal of sinks as fruit growth commences has on photosynthesis is much less addressed. The objective was to remove Shiraz bunches at the rapid growth stage and compare photosynthetic performance of vines with and without fruit. Photosynthetic responses to CO2 concentrations and leaf temperatures were followed across the season to determine performance with changes in fruit sink demand. Assimilation across all temperatures peaked in spring and declined progressively throughout the season. Detaching bunches removed about 160 g dry matter from vines and this effected assimilation immediately, a decrease of about 20% which was sustained over 30 days. For fruiting vines, bunch biomass was severely impeded by a sustained heat event, reducing berry sugar content by 50% and may have impacted on the vines without bunches, thus obscuring the effects of sink removal. There was no evidence that assimilation was impaired by the heat event but the sink removal reduced RuBP carboxylation and regeneration, probably resulting from an inactivation of Rubisco. In contrast to removal of sinks in early development, the late removal appeared to inhibit photosynthetic acclimation of the Shiraz vines, reflecting maturity of the leaves.

Whole-Canopy Source-Sink Balance at Bloom Dictates Fruit Set in cv. Pinot noir Subjected to Early Leaf Removal

Severe prebloom leaf removal dramatically affects the source-sink balance in grapevines, leading to a reduction in fruit set. In this study, carried on for two consecutive years, the impact of defoliation at bloom was evaluated with the objective to assess the capacity of developing inflorescences to attract photosynthates from adjacent shoots subjected to varying source/sink manipulations. In Pinot noir, trained to a bilateral cordon, untreated vines (UT - UT) were compared to a treatment where shoots on one-half of the vines were subjected to the removal of 10 basal leaves at bloom (UT - LR). Another set of vines underwent sink removal (inflorescences and shoot apex) at bloom on half of the shoots by hand thinning (TFR - UT). A final treatment consisted of removing 10 basal leaves on half of the shoots and removing sinks on the other half of the canopy (TFR - LR). Following treatment application, shoot leaf area retained was about 40% of the total in UT - LR and TFR – LR. UT - LR reduced the whole canopy leaf area available per inflorescence by approximately 44% when compared to UT – UT. TFR - LR did not affect this balance. In UT – LR, fruit set was significantly reduced (-36% as compared to UT - UT), whereas it was unaffected by TFR - LR and TFR - UT. Independently of treatments, fruit set in both seasons was correlated with whole-canopy leaf area per inflorescence at bloom and not with the single shoot leaf area retained after early leaf removal.

Effect of Sink Removal and Magnesium Spraying on Photosynthetic Pigments and Sugar Yield of Two Sweet Sorghum Cultivars

Effect of Sink Removal and Magnesium Spraying on Photosynthetic Pigments and Sugar Yield of Two Sweet Sorghum Cultivars

1251. Contaminated Sinks May be an Environmental Source for Serial Transmission of Carbapenem-Resistant Enterobacteriaceae (CRE) to ICU Patients

BackgroundWe performed an investigation after noting an increase in hospital-onset (HO) KPC-producing Enterobacteriaceae (KPC-E) infections in patients admitted to a tertiary referral hospital in North Carolina.MethodsWe defined pre-outbreak (January 1, 2017–June 30, 2017), outbreak (July 1, 2017–October 31, 2017), and post-outbreak (November 1, 2017–March 31, 2018) phases. A clinical case was defined as any positive clinical culture for KPC-E. HO was defined as a positive clinical or surveillance culture collected on hospital day ≥3. Patients were mapped in space and time to inform targeted environmental sampling. Whole-genome sequencing (WGS) was performed on selected KPC K. pneumoniae environmental and patient isolates to determine relatedness.In October 2017, a CRE prevention bundle was implemented that included daily communication of CRE patient movement, increased audits/feedback of HCW compliance with hand hygiene, enhanced cleaning and disinfection in CRE rooms and high-risk units with bleach and UVC disinfection, and weekly rectal surveillance screens in four adult ICUs.Results0.67 clinical cases of KPC-E per month were observed during the pre-outbreak period compared with 3.75 clinical cases of KPC-E per month during the outbreak period. K. pneumoniae was the most common species (Figure 1). Mapping of patients revealed probable direct and indirect transmission between patients in multiple hospital units (Figure 2). three patients who were non-sequentially admitted to the same ICU room over a 12-week span acquired KPC K. pneumoniae (Figure 2). Environmental cultures from the in-room sink drain and P-trap grew KPC K. pneumoniae that was related to the patient isolates by WGS; the sink was removed. Although no additional clinical cases of KPC-E occurred after full implementation of the bundle and sink removal, we continued to observe acquisition of KPC-E rectal colonization in all four ICUs (Figure 3).ConclusionWe describe a multispecies outbreak of KPC-E that was mitigated through evidence-based CRE control measures and removal of a colonized sink. However, ongoing low-level presumed transmission of KPC points to persistent environmental sources. Additional study is needed to understand the prevalence of CRE in hospital sinks, factors that drive drain colonization, and contribution of CRE in a sink to nosocomial transmission. Disclosures All authors: No reported disclosures.

Reduced rate of intensive care unit acquired gram-negative bacilli after removal of sinks and introduction of \u2018water-free\u2019 patient care

BackgroundSinks in patient rooms are associated with hospital-acquired infections. The aim of this study was to evaluate the effect of removal of sinks from the Intensive Care Unit (ICU) patient rooms and the introduction of ‘water-free’ patient care on gram-negative bacilli colonization rates.MethodsWe conducted a 2-year pre/post quasi-experimental study that compared monthly gram-negative bacilli colonization rates pre- and post-intervention using segmented regression analysis of interrupted time series data. Five ICUs of a tertiary care medical center were included. Participants were all patients of 18 years and older admitted to our ICUs for at least 48 h who also received selective digestive tract decontamination during the twelve month pre-intervention or the twelve month post-intervention period. The effect of sink removal and the introduction of ‘water-free’ patient care on colonization rates with gram-negative bacilli was evaluated. The main outcome of this study was the monthly colonization rate with gram-negative bacilli (GNB). Yeast colonization rates were used as a ‘negative control’. In addition, colonization rates were calculated for first positive culture results from cultures taken ≥3, ≥5, ≥7, ≥10 and ≥14 days after ICU-admission, rate ratios (RR) were calculated and differences tested with chi-squared tests.ResultsIn the pre-intervention period, 1496 patients (9153 admission days) and in the post-intervention period 1444 patients (9044 admission days) were included. Segmented regression analysis showed that the intervention was followed by a statistically significant immediate reduction in GNB colonization in absence of a pre or post intervention trend in GNB colonization. The overall GNB colonization rate dropped from 26.3 to 21.6 GNB/1000 ICU admission days (colonization rate ratio 0.82; 95%CI 0.67–0.99; P = 0.02). The reduction in GNB colonization rate became more pronounced in patients with a longer ICU-Length of Stay (LOS): from a 1.22-fold reduction (≥2 days), to a 1.6-fold (≥5 days; P = 0.002), 2.5-fold (for ≥10 days; P < 0.001) to a 3.6-fold (≥14 days; P < 0.001) reduction.ConclusionsRemoval of sinks from patient rooms and introduction of a method of ‘water-free’ patient care is associated with a significant reduction of patient colonization with GNB, especially in patients with a longer ICU length of stay.

Effects of low sink demand on leaf photosynthesis under potassium deficiency

The interaction between low sink demand and potassium (K) deficiency in leaf photosynthesis was not intensively investigated, therefore this interaction was investigated in winter oilseed rape (Brassica napus L.). Plants subjected to sufficient (+K) or insufficient (−K) K supply treatments were maintained or removed their flowers and pods; these conditions were defined as high sink demand (HS) or low sink demand (LS), respectively. The low sink demand induced a lower photosynthetic rate (Pn), especially in the −K treatment during the first week. A negative relationship between Pn and carbohydrate concentration was observed in the −K treatment but not in the +K treatment, suggesting that the decrease in Pn in the −K treatment was the result of sink feedback regulation under low sink demand. Longer sink removal duration increased carbohydrate concentration, but the enhanced assimilate did not influence Pn. On the contrary, low sink demand resulted in a high K concentration, slower chloroplast degradation rate and better PSII activity, inducing a higher Pn compared with HS. Consequently, low sink demand decreased leaf photosynthesis over the short term due to sink feedback regulation, and potassium deficiency enhanced the photosynthetic decrease through carbohydrate accumulation and a lower carbohydrate concentration threshold for initiating photosynthesis depression. A longer duration of limited sink demand and sufficient potassium supply resulted in a higher photosynthesis rate because of delayed chloroplast degradation. This finding indicates that the nutritional status plays a role in leaf photosynthesis variations due to sink-source manipulation.

Efficient hybrid breaching-filling sink removal methods for flow path enforcement in digital elevation models

Efficient hybrid breaching-filling sink removal methods for flow path enforcement in digital elevation models

Carbon sink removal: Increased photosynthetic production of lactic acid by Synechocystis sp. PCC6803 in a glycogen storage mutant

Deletion of pathways for carbon-storage in the cyanobacterium Synechocystis sp. PCC6803 has been suggested as a strategy to increase the size of the available pyruvate pool for the production of (heterologous) chemical commodities. Here we show that deletion of the pathway for glycogen synthesis leads to a twofold increased lactate production rate, under nitrogen-limited conditions, whereas impairment of polyhydroxybutyrate synthesis does not.

Effects of source and sink removal on yield attributes and yield of mungbean [Vigna radiata(L.) Wilczek

Field experiments were conducted to investigate the effect of source (leaf) and sink (flower and pod) removal on some morphological characters, and yield and its attributes in high and low yielding mungbean genotypes grown under sub-tropical condition. Four levels of defoliation (0, 8, 16 and 33%), four levels of deflowering (no deflowering, deflowering of all opened flowers borne up to 10th or 15th or 20th nodes in a raceme), and four levels of depodding (no depodding, depodding of all pods for 5 or 10 or 15 days after anthesis) were employed. The results showed that defoliation had no significant effect on seed yield in high yielding genotype, while it reduced the yield in low yielding one under 16 and 33% defoliation. Deflowering up to 10th nodes had no significant effect on seed yield though deflowering beyond 10th nodes in a raceme reduced the seed yield in high yielding mungbean genotype; low yielding genotype exhibited reduced seed yield under any level of deflowering. Depodding up to five days from anthesis had no negative effect on seed yield though depodding beyond this period reduced the yield depending upon the magnitude of depodding. Pod number per plant, number of seeds per pod and 1000-seed weight were the yield attributes sensitive to deflowering and depodding. The results suggest that mungbean plant, especially high yielding genotypes, can compensate seed yield to moderate source loss and partial sink loss.

Fruit Regulates Bud Sprouting and Vegetative Growth in Field-Grown Loquat Trees (Eriobotrya japonica Lindl.): Nutritional and Hormonal Changes

The effects of fruit on bud sprouting and vegetative growth were compared on fruiting and defruited loquat trees from fruit set onward. Carbohydrate and nitrogen content in leaves and bark tissues and hormone concentrations were studied during the fruit development and vegetative growth periods. On defruited trees, a significant proportion of buds sprouted in winter, whereas buds from fruiting trees sprouted only in the spring when fruit reached its final size. Furthermore, when panicles were completely removed in autumn, the buds also sprouted. In addition, fruit directly affected vegetative growth by reducing shoot length. An effect of sink removal (flower or fruit) promoting bud sprouting, regardless of the season, was then demonstrated. Neither soluble sugar concentration nor nitrogen fraction concentration in leaves or bark tissues was related to bud sprouting, but a certain nutritional imbalance was observed during the most active period of fruit development. Moreover, fruit sink activity significantly modified hormone content by increasing indole-3-acetic acid (IAA) and reducing zeatin concentrations, resulting in a higher IAA/zeatin ratio parallel to the lower bud sprouting intensity. Therefore, these changes caused by fruit removal are all related to vegetative growth, but there is no evidence that they are responsible for bud burst.

An effective depression filling algorithm for DEM-based 2-D surface flow modelling

Abstract. The surface runoff process in fluvial/pluvial flood modelling is often simulated employing a two-dimensional (2-D) diffusive wave approximation described by grid based digital elevation models (DEMs). However, this approach may cause potential problems when using the 2-D surface flow model which exchanges flows through adjacent cells, with conventional sink removal algorithms which also allow for flow exchange along diagonal directions, due to the existence of artificial depression in DEMs. In this paper, we propose an effective method for filling artificial depressions in DEM so that the problem can be addressed. We firstly analyse two types of depressions in DEMs and demonstrate the issues caused by the current depression filling algorithms using the surface flow simulations from the MIKE SHE model built for a medium-sized basin in Southeast England. The proposed depression-filling algorithm for 2-D overland flow modelling is applied and evaluated by comparing the simulated flows at the outlet of the catchment represented by DEMs at various resolutions (50 m, 100 m and 200 m). The results suggest that the existence of depressions in DEMs can substantially influence the overland flow estimation and the new depression filling algorithm is shown to be effective in tackling this issue based upon the comparison of simulations for sink-dominated and sink-free DEMs, especially in the areas with relatively flat topography.