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The effect of heat treatment on the mechanical properties of two high-carbon-containing (1.5 and 3 at%) single-phase face-centered cubic (fcc) Fe40.4Ni11.3Mn34.8Al7.5Cr6 high-entropy alloys is reported in this study. In the cold-rolled (CR) condition, the 1.5 and 3 at% C-containing alloys, referred to as CR1 and CR2, respectively, demonstrated yield strength values of 1,423 and 1,197 MPa, respectively. The corresponding values of elongation to failure was noted to be 4.05 and 4.46%, respectively. Upon heat treatment at 1,050°C, the CR1 and CR2 samples, referred to as HT1 and HT2 in the heat-treated (HT) condition, demonstrated yield strength values of 358 and 327 MPa, respectively. The elongation to failure of HT1 and HT2 was found to be 37.2 and 26.4%, respectively. The change in mechanical properties brought about by heat treatment was understood by studying the phase composition, microstructure, and crystallographic texture of the material in the CR and HT conditions. Despite the high-temperature heat treatment, the Fe40.4Ni11.3Mn34.8Al7.5Cr6 alloy retained a single-phase structure, indicating good phase stability. However, heat treatment caused a change in the grain structure. The CR materials exhibited an elongated grain structure, whereas the HT materials had an equiaxed microstructure. The CR and HT samples were found to exhibit a weak crystallographic texture although heat treatment had caused the {111} poles to orient themselves parallel to the rolling plane, whereas the CR material had a distribution of {200} poles at 45° to the rolling plane.

A 53-year-old woman is admitted with a serum creatinine of 16 mg/dl. Seven months earlier, she was diagnosed with heart failure and started on several medications, including Hydralazine. Laboratory studies revealed the presence of dual Anti-Neutrophil Cytoplasmic Antibodies (anti-MPO and anti-PR3), anti-nuclear and anti-histone antibodies. The clinical diagnosis was Drug-Induced ANCA Vasculitis (DIAV). Kidney histology, however, did not reveal crescents, but showed characteristic features of Alport’s syndrome.

A new species of barb Pethia lutea is described from the Kundalika River in the northern part of the Western Ghats. The new species can be distinguished from its congeners in India based on a combination of characters including a distinct humped nape, absence of barbels, complete lateral line, lips thick, lateral fold on snout, 19-22 lateral line scales, 8 predorsal scales, 9-10 prepelvic scales, 14-15 preanal scales, 4-4.5 transverse scale rows between lateral line and dorsal fin origin, 2.5-3 transverse scale rows between lateral line and pelvic fin base, 6-9 pair of serrae on the distal half of the dorsal fin spine, 13-15 branched pectoral fin rays, 7 branched pelvic fin rays, 4+26 total vertebrae, 4+13 abdominal and 13 caudal vertebrae, body with one vertical humeral and one caudal blotch and dorsal fin without any bands or blotches. Additionally, we provide new records of Pethia punctata from the rivers of Maharashtra State along with a description of its osteology.

The Wayanad Mahseer Neolissochilus wynaadensis (Day, 1873) is an endemic cyprinid fish that occurs in the upland streams and rivers of the southern region of the Western Ghats. This species has been listed as Critically Endangered on the IUCN Red List of Threatened Species due to its restricted distribution and heavy declines in populations. Like many large cyprinids of the Western Ghats, N. wynaadensis is poorly known and documented, with very few verified records and voucher specimens. Based on specimens recently collected from Wayanad, Kerala, the type locality, as well as two additional locations in the Kodagu District of Karnataka; we provide information on the current distribution, phylogenetic position, threats and conservation. An updated conservation assessment of this species following the IUCN Red List categories and criteria is also provided.

Community Reserves and Conservation Reserves illustrate a community-based co-management model, a first of its kind within the protected area (PA) network of India. Such reserves mark a shift towards an inclusive and decentralised approach within PAs in the country. Three such reserves in southern India: the Aghanashini Lion-tailed Macaque Conservation Reserve, Kadalundi-Vallikunnu Community Reserve and Thirupaddaimaradur Conservation Reserve, were selected to examine the reasons for their creation, management and stakeholder dynamics, with an aim to review their productivity and potential replicability. The study was carried out through semi-structured interviews with Forest Department officials, local community members and researchers working in the three reserves. Insufficient interaction between the stakeholders appeared to be a common issue in two reserves. The functioning of the reserves was also influenced, and in some cases negatively affected, by local politics. Financial stability was crucial in the functioning of reserves, as was consistency in interaction and appropriate monitoring of management plans. These elements are recommended for sustaining such reserves and creating community-based management systems for conservation, to support an inclusive approach to PA management.

The Red Canarese Barb, Hypselobarbus thomassi (Day, 1874) is an endemic cyprinid fish of the rivers of the Western Ghats of India, which has been listed as ‘Critically Endangered’ in the IUCN Red List of Threatened Species. Like many of its congeners, H. thomassi is poorly known with very few verified records and voucher specimens in the past decades. Based on fresh materials collected from three west flowing rivers of Kerala, we provide information on its identity, distribution, phylogenetic position, threats and conservation. An updated conservation assessment of this species following the IUCN Red List criteria is also provided.

Redline Torpedo Barbs (Teleostei: Cyprinidae), comprising of two species, Puntius denisonii and P. chalakkudiensis, and six evolutionarily distinct lineages are endemic to the streams of the Western Ghats freshwater ecoregion in peninsular India. Based on molecular and osteological evidence, we demonstrate that these barbs comprise a distinct genus, for which we propose the name Sahyadria.

We present here a comprehensive account of the diversity, distribution, threats, and suggest conservation measures for the fishes of Bharathapuzha, the largest west flowing river in the southern Indian state of Kerala. A total of 117 species under 43 families and 81 genera were recorded from the river, of which 98 were primary freshwater and 19 were secondary freshwater and/or diadromous species. Six species of non-native fish were also recorded, of which three were exotic to the country and three were transplanted from the gangetic plains. Twenty-eight percent (S = 33) of species that occur in the Bharathapuzha are endemic to the Western Ghats, while three species (Balitora jalpalli, Mesonoemacheilus remadevii and Pseudolaguvia austrina) are restricted in their distribution to the river system. A little more than one-tenth (11%; S = 13) of species that occur in the river are listed under various threatened categories on the IUCN Red List. As part of this study, we also extend the distribution range of Osteochilichthys longidorsalis to the Bharathapuzha River system, based on its collection from the Thoothapuzha tributary. Several anthropogenic stressors including deforestation and loss of riparian cover, dams and other impoundments, pollution, sand mining, non-native species and destructive fishing practices are threatening the rich ichthyofaunal diversity and endemism in the Bharathapuzha. There is hence an urgent need to develop and implement conservation plans, some of which are discussed.

The length-weight relationship (LWR) and length-length relationships (LLR) of three snakehead fishes, Channa diplogramma, C. marulius and C. striata, exploited by small-scale fishers in the riverine reaches of Lake Vembanad, Kerala were studied using the allometric growth equation Y = aXb. Our analysis shows that the LWR of C. diplogramma and C. marulius is nonisometric with exponents much smaller than the cubic value (b = 3), while that of C. striata is isometric. Channa marulius showed a definite change in LWR with size, with smaller fish growing with positive allometric exponents (b greater than 3) and larger individuals having negative allometric relationship (b less than 3), indicating a possible age-related change in growth pattern. In the case of LLR, all three snakehead species showed non-isometric growth patterns. The caudal fin did not grow substantially with increasing fish length.

Hypselobarbus lithopidos (Day, 1874) is a poorly known cyprinid fish endemic to the rivers of the Western Ghats of India. This species is assessed as Data Deficient in the IUCN Red List of Threatened Species with a note that it could be possibly extinct. Here, we provide information on a recent collection of this species from the type locality, and discuss its current distribution, ecology, threats and conservation. A revised Red List status for the species is also proposed.

The Nilgiri Mystus, Hemibagrus punctatus, a rare bagrid catfish endemic to the Western Ghats, has been currently listed in the IUCN Red List, as Critically Endangered with a possibility that it could be extinct. The last validated record of H. punctatus was known to be in 1998, and several surveys since then have not been able to collect the species from its native range. In this paper, we provide information on new records of this rare catfish from the Western Ghats after a period of 14 years, and discuss its distribution, ecology and conservation. An updated conservation assessment of this species following the IUCN Red List Criteria is also provided.

Biodiversity conservation is a collaborative effort involving numerous stakeholders. Attempting to balance different interests and developing effective working relationships between stakeholders is vital for successfully addressing issues of biodiversity conservation. Presently, biodiversity conservation in India is monopolised by state forest departments (FD) with negligible participation from local communities (who are directly affected by forest laws) and researchers (whose work can improve conservation). This study examines the efficiency of multiple stakeholders-local communities, FD, researchers and politicians in conserving biodiversity at the Anamalai - Palni Hills of the southern Western Ghats in Tamil Nadu. Efficiency here is defined as the amount of positive assistance stakeholders provide towards conserving biodiversity. A systematic sampling strategy through self-administered questionnaires was used to understand stakeholders perception of one another and the challenges they faced. The results highlight the FD as having the highest efficiency in conserving biodiversity followed by local communities, researchers and lastly, political leaders. Stakeholder evaluation of one another efficiency revealed a homogenous opinion towards local communities and the FD. However, a considerable difference was observed towards researchers whereby their efficiency was rated lower by local communities in comparison to the FD. Dependency on forest resources that was curbed by the FD invariably affected the attitude of local communities towards biodiversity conservation. On the other hand, low pay rolling schemes, inadequate facilities and political interference hinder the management capabilities of the FD. Increased research and outreach activities would benefit Kodaikanal and Theni, provided a collaborative effort to conserve biodiversity is pursued.

Travancoria elongata is a rare balitorid loach endemic to the Kerala part of the Western Ghats, where it was till date known to occur in two locations, one each in the Chalakudy and Periyar River. The species was listed in the IUCN Red List as Endangered as a result of its restricted distribution, and continuing decline in the quality of habitats in its range. Here we present new records of this species from three locations (Mlappara, Thanikkudy and Mankulam) in the Periyar River. Although Mlappara and Thanikkudy are located within the highly protected Periyar Tiger Reserve, the third site (Mankulam) does not have any legal protection, and is subjected to threats such as agro-based pollution and proliferation of exotic species.

TA new species of stone loach (Cypriniformes: Balitoridae), Balitora jalpalli, is described from Kunthi tributary of Bharatapuzha River located inside Silent Valley National Park in the southern Western Ghats of Kerala, India. It can be distinguished from known Indian species of Balitora by five major characters: head length, caudal peduncle depth, maximum head width and difference in number and pattern of bands on the dorsal side. The new species is distinct in having two unbranched and 8-9 branched ventral fin rays, nine unbranched and 10-11 branched pectoral fin rays and 66 lateral line scales, a caudal peduncle length to depth ratio of 2.3-2.7, anal fin to anus distance 3.3-4.7 % SL, least depth of caudal peduncle 6.3-6.7 % SL, length of caudal peduncle 15.4-17.2 % SL, length of upper caudal lobe 22.1-22.8 % SL, maximum head width 67.9-74.1 % HL, eye diameter 12.1-14.2 % HL, and gape 31.3-31.5 % HL.

In this communication, we document the local knowledge, attitudes and perceptions of slender lorises among the indigenous Kani community in the southern Western Ghats; document new records of Loris lydekkerianus lydekkerianus in the Agasthyamalai Hills; and discuss in detail a poorly known threat to these primates. Although not kept as pets due to their physical appearance, and belief that they would bring bad luck, the Kani community however captured slender lorises for wildlife photographers. Similar instances of loris abuse in various parts of south India were revealed upon analyzing photographs from a popular internet-based wildlife photography site. We recommend that strict guidelines be formulated for photographing lorises, and suggest that novel and ethical tourism initiatives be set up involving local communities to cater to wildlife photographers and tourists.

In this study, we used local ecological knowledge to determine the status, habitats, threats and consumption of two range-restricted and threatened chelonians, Vijayachelys silvatica and Indotestudo travancorica from two forest divisions of Kerala, that occur in the Western Ghats. Of these terrestrial species, I. travancorica was more abundant, preferred and consumed in the study region. Fire was the major perceived threat to these species, followed by human consumption. Contrary to the literature, V. silvatica was considered common and encountered more often during the fruiting season of specific plants, and in areas where temperatures were low. We also found that photographs, rather than local names, were important for species identification associated with such knowledge surveys.

Based on the annual length frequency data collected from three major fish landing centres along the River Periyar, draining the southern Western Ghats, the von Bertalanffy growth function (VBGF) estimates of Horobagrus brachysoma were worked out as asymptotic length (La) = 422mm total length, growth co-efficient (K) = 0.55 yr-1 and growth performance index (ø) = 4.99. The total mortality rate (Z) was estimated at 5.64 yr-1, natural mortality rate (M) at 1.04 yr-1, fishing mortality (F) at 4.60 yr-1, and exploitation rate (E) at 0.82 yr-1. Yield per recruit (expected lifetime yield per fish recruited in the stock at a specific age) analysis showed an excessive fishing effort. Using the analysis of probability of capture of each length class, the length at first capture (Lc) of H. brachysoma was estimated to be 110mm. An indication of both growth and recruitment fishing is provided by the dominance of year 1 class in the exploited population and the capture of immature individuals below first maturity. Management of H. brachysoma fishing should include setting of a minimum mesh size limit of 160â180 mm for gill nets as well as a closed season starting from the month of May till August aimed at protecting the spawning stock. This study on H. brachysoma, an endemic and threatened catfish of peninsular India, provides hard evidence that species targeted by artisanal fishermen, in small-scale tropical riverine fisheries, are vulnerable to overexploitation.

This study presents fundamental information on the reproductive biology of Puntius denisonii, an endemic and threatened aquarium fish of the Western Ghats Hotspot. Results are based on the observations from three river systems, Chandragiri, Valapattannam and Chaliyar. Maximum observed total length in P. denisonii was 162mm and 132mm for males and females, respectively. Males attained sexual maturity at a lower size than females with mean size at first maturity determined as 85.33 plus or minus 1.52 mm for males and 95.66 plus or minus 1.15 mm for females. Puntius denisonii spawned from October to March with minor differences in the peak breeding months between the three river systems, which were studied. Sex ratio deviated significantly from 1:1 and was skewed in favour of males. Absolute fecundity varied from 376 (fish of 102mm total length) to 1098 (fish of 106mm total length) eggs. Currently, the closed seasons for P. denisonii have been put in place during June, July and October based on the (mis)assumption that the species breeds during these three months. However, the results of the present study have helped us to understand more about the reproductive biology of the species so as to recommend more appropriate seasonal closures. The months from October until March need to be designated as a closed season for protecting the breeding population of P. denisonii.

We report the results of an ichthyofaunal inventory carried out in the Achankovil Reserve Forest in the southern Western Ghats as part of a Critical Ecosystem Partnership Fund Project on lesser known freshwater fishes of Kerala . Forty-six species of freshwater fish, belonging to 17 families and 31 genera were collected from 11 sites inside the Achankovil Reserve Forest. Family Cyprinidae dominated with 21 species, followed by Bagridae, Balitoridae and Channidae (three species each). Out of the 46 species, 14 were endemic to the Western Ghats, three were endemic to Kerala region and one was exotic to the country. In this paper, we also report the range extension of an endemic cyprinid, Puntius chalakkudiensis to the Achankovil River and the Achankovil Reserve Forest. The fish diversity of this region is higher than many protected areas within southern Western Ghats, and stresses the need for immediate protection and monitoring programs.

Length weight relationship (LWR) and condition factor were studied in Nilgiri Garra, Garra gotyla stenorhynchus (Jerdon), from the rivers Chaliyar and Bhavani flowing through the Western Ghats Biodiversity Hotspot. The regression equation for LWR of the Nilgiri Garra from Chaliyar River was estimated as Log Wt = 2.920 Log L - 1.854, while those from Bhavani River as Log Wt = 2.594 Log L - 1.538. Although, the ‘b’ value observed from west flowing Chaliyar River (2.920) was higher than that from east flowing Bhavani River (2.594), they were statistically insignificant. Similarly, the Condition Factor (K) was higher in Bhavani populations (2.177) compared to Chaliyar (2.087), but were also statistically insignificant. The results indicated that populations of G. gotyla stenorhynchus in Chaliyar River followed an isometric like growth pattern with ‘b’ values close to cubic law. However local populations of the same species in Bhavani River are under stress as indicated by comparatively lower ‘b values. This difference in ‘b’ value between the two river populations may be due to the differences in physical habitat features of the locations from where they were sampled, including altitude, physical habitat features, water quality and their combined influence on the availability of food materials as well as stock/population differences and yet to be identified stressors.

Indiscriminate and illegal farming of the African Catfish Clarias gariepinus, in central Kerala has now resulted in the escape and spread of the species into Vembanad Lake, a large brackish water wetland and inland fish diversity hotspot. We collected 17 individuals of C. gariepinus ranging in size from 200 to 750 mm from different locations in the southern sector of the lake during a field survey conducted in 2007. Samples comprised of mature specimens of both sexes indicating their reproductive potential in the study area. The possible impacts of spread of C. gariepinus into natural water bodies of Kerala, especially the Vembanad Lake, and options for their management are discussed.

The freshwater fish fauna of New Amarambalam Reserve Forest (NARF) in the Southern Western Ghats (Kerala) is constituted by 43 species belonging to 13 families and 28 genera. Family Cyprinidae dominated with 20 species followed by Balitoridae and Bagridae (four species each). NARF may harbour higher freshwater fish species diversity than in protected areas in North Kerala. The area around Maanchery in the Karimpuzha tributary of River Chaliyar needs to be designated as a priority area for freshwater fish conservation.

Anaphylaxis is a life-threatening event that can occur anytime during pregnancy. It has been reported following administration of various substances with adverse maternal and neonatal consequences. It should be considered in the differential diagnosis of intrapartum collapse. We encountered a case of severe anaphylactic reaction following a routine cesarean section. It is very important that all members of the perinatal team are aware of early recognition and management of anaphylactic reaction. We think that it is important to highlight this as a further case report of severe anaphylactic reaction to a colloid solution and discuss the pathophysiology and management.

Semen samples (324 samples) from 27 Holstein friesian bulls were studied for bacterial comtamination. Both gram positive and gram negative organisms were isolated from the samples

The triblock copolymer Pluronic F127 (PF127) is frequently used in colloidal and pharmaceutical formulations. Concentrated aqueous solutions of PF127 (>15 wt %) are known to undergo thermogelling(i.e., a sol-to-gel transition upon heating), which is attributed to the formation of a volume-filling cubic array of micelles. Here, we report that thermogelling can occur at much lower PF127 concentrations (1.2 to 8 wt %) if nanoparticles of laponite (25-nm-diameter disks) are also present in the formulation. Thermogelling in laponite/PF127 mixtures requires each component to be present above a minimum level. The gels have moduli around 100 Pa, and they can be reversibly liquefied to sols upon cooling. Rheological techniques, small-angle neutron scattering (SANS), and transmission electron microscopy (TEM) are used to characterize the thermogels. We attribute the onset of thermogelling to depletion flocculation of the laponite particles into a network by spherical micelles of PF127. [ABSTRACT FROM AUTHOR]

Telechelic associating polymers (hydrophilic ethoxylated backbone, hydrophobic n-alkyl end-groups) form viscous solutions in water due to associations between the hydrophobes. The addition of α-, β-, or γ-cyclodextrin (CD) substantially reduces the solution viscosity because the CD molecules envelop and sequester the hydrophobes in their hydrophobic cavities. The present paper explores the variation in polymer−CD solution viscosity with temperature. We find that, in the case of α-CD alone, the solutions show “thermothickening”, i.e., the viscosity increasesfrom 25 to ca. 60 °C whereupon it reaches a peak value and then drops. In contrast, solutions with β- and γ-CD show monotonic drops in viscosity upon heating. At a fixed polymer content, the thermothickening is higher for higher α-CD concentrations. We have also studied how surfactants and lipids impact the thermothickening. Addition of single-tailed micelle-forming surfactants causes the viscosity to revert to the more typical decreasing trend with temperature. However, addition of double-tailed lipids to a polymer/α-CD solution accentuates the thermothickening behavior. The thermothickening is explained by the propensity of α-CDs to unbind from the hydrophobes and form inclusion complexes with the polymer backbone as the temperature is raised. [ABSTRACT FROM AUTHOR]

Gel formation by surfactant molecules is argued to be a process similar to micellization rather than crystallization; it is controlled by thermodynamics rather than kinetics. The properties of surfactant-based gels are compared with those of gels with crystalline fibrillar networks, and questions associated with the nature of these gels are raised. [ABSTRACT FROM AUTHOR]

Strain-stiffening, that is, an increase in material stiffness at large deformations, is a property of many biological materials. Currently, model systems for the study of this phenomenon are elastic networks (gels) of semiflexible filamentous biopolymers such as actin, keratin, or fibrin. Here, we demonstrate strain-stiffening in a class of viscoelasticsolutions, comprising reverse wormlike micelles. These structures are formed by the coassembly of the physiological surfactants, lecithin and bile salt, in an organic solvent, cyclohexane. In contrast to the biopolymer gels, the networks here are transient and are formed by the physical entanglement of relatively flexible worms. Our results suggest that neither a permanent network nor a high filament rigidity is required for strain-stiffening. We suggest a different origin, based on a temporary strain-induced increase in the volume fraction of entangled worms. Our system can also serve as a convenient synthetic model for future studies into this phenomenon. [ABSTRACT FROM AUTHOR]

For the first time, an interpenetrating phase polymer nanocomposite formed by the percolation of multiwalled carbon nanotubes (MWCNTs) in polystyrene (PS) has been quantitatively characterized through electrical conductivity measurements and melt rheology. Both sets of measurements, in conjunction with scanning electron microscopy (SEM) images, indicate the presence of a continuous phase of percolated MWCNTs appearing at particle concentrations exceeding 2 vol% MWCNTs in PS. To quantify the amount of this continuous phase present in the PS/MWCNT composite, electrical conductivity data at various MWCNT concentrations, b, are correlated with a proposed degree of percolation, \bar {C}(\beta) , developed using a conventional power-law formula with and without a percolation threshold. To quantify the properties of the interpenetrating phase polymer nanocomposite, the PS/MWCNT composite is treated as a combination of two phases: a continuous phase consisting of a pseudo-solid-like network of percolated MWCNTs, and a continuous PS phase reinforced by non-interacting MWCNTs. The proposed degree of percolation is used to quantify the distribution of MWCNTs among the phases, and is then used in a rule-of-mixtures formulation for the storage modulus, G''(\beta,\bar {C}(\beta), \omega) , and the loss modulus, G''''(\beta,\bar {C}(\beta),\omega) , to quantify the properties of the continuous phase consisting of percolated MWCNTs and the continuous PS phase reinforced by non-interacting MWCNTs from the experimental melt rheology data. The properties of the continuous phase of percolated MWCNTs are indicative of a scaffold-like microstructure exhibiting an elastic behavior with a complex modulus of 360 kPa at lower frequencies and viscoplastic behavior with a complex viscosity of 6 kPa s rad[?]1 at higher frequencies, most likely due to a stick-slip friction mechanism at the interface of the percolated MWCNTs. Additional evidence of this microstructure was obtained via scanning electron microscopy. This research has important implications in providing a new methodology based on the electrical and rheological properties of the polymer nanocomposite for quantifying the continuous phase formed by the percolation of new functionalized nanostructures being developed for: (a) controlling the percolation of the nanostructures through self-assembly, (b) enhancing their interaction with the continuous reinforced polymer phase, (c) enhancing the cohesion between nanostructures. [ABSTRACT FROM AUTHOR]

The authors demonstrate strong adhesion of cationic hydrogels to bovine tissues under a DC electric field. Such electroadhesion can be reversed by switching the polarity of the field. This approach could enable simpler surgeries, where sutures are not needed.

Management of patients with single ventricle physiology after surgical palliation is challenging. Arginine vasopressin has gained popularity in recent years as a non-catecholamine vasoactive medication due to its unique properties. However, data regarding its use in the pediatric population is limited. Therefore, we designed a survey to explore whether and how clinicians use this medication in intensive care units for the postoperative management of single ventricle patients. This international survey aimed to assess usage, practices, and concepts related to arginine vasopressin in pediatric intensive care units worldwide. Directors of pediatric intensive care units who are members of the following international professional societies: European Society of Pediatric Neonatal Intensive Care, Association for European Pediatric and Congenital Cardiology, and Pediatric Cardiac Intensive Care Society were invited to participate in this survey. Of the 62 intensive care unit directors who responded, nearly half use arginine vasopressin in the postoperative management of neonatal single ventricle patients, and 90% also use the drug in subsequent surgical palliation. The primary indications are vasoplegia, hemodynamic instability, and refractory shock, although it is still considered a second-line medication. Conceptual benefits include improved hemodynamics and end-organ perfusion and decreased incidence of low cardiac output syndrome. Those practitioners who do not use arginine vasopressin cite lack of availability, fear of potential adverse effects, unclear indication for use, and lack of evidence suggesting improved outcomes. Both users and non-users described increased myocardial afterload and extreme vasoconstriction as potential disadvantages of the medication. Despite the lack of conclusive data demonstrating enhanced clinical outcomes, our study found arginine vasopressin is used widely in the care of infants and children with single ventricle physiology after the first stage and subsequent palliative surgeries. While many intensive care units use this medication, few had protocols, offering an area for further growth and development.