Unusual Cluster Research Articles

Synthesis and Characterization of a Terminal Iron(II)-PH2 Complex and a Series of Iron(II)-PH3 Complexes.

Reported is the reaction of a series of iron(II) bisphosphine complexes with PH3 in the presence of NaBArF4 [where BArF4 = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate]. The iron(II) bisphosphine reagents bear two chlorides or a hydride and a chloride motif. We have isolated six different cationic terminal-bound PH3 complexes and undertaken rigorous characterization by NMR spectroscopy, single crystal X-ray diffraction, and mass spectrometry, where the PH3 often remains intact during the ionization process. Unusual bis- and tris-PH3 complexes are among the compounds isolated. Changing the monophosphine from PH3 to PMe3 results in the formation of an unusual Fe7 cluster, but with no PMe3 being ligated. Finally, by using an iron(0) source, we have provided a rare example of a terminally bound iron-PH2 complex.

Flagging unusual clusters based on linear mixed models using weighted and self-calibrated predictors.

Statistical models incorporating cluster-specific intercepts are commonly used in hierarchical settings, for example, observations clustered within patients or patients clustered within hospitals. Predicted values of these intercepts are often used to identify or "flag" extreme or outlying clusters, such as poorly performing hospitals or patients with rapid declines in their health. We consider a variety of flagging rules, assessing different predictors, and using different accuracy measures. Using theoretical calculations and comprehensive numerical evaluation, we show that previously proposed rules based on the 2 most commonly used predictors, the usual best linear unbiased predictor and fixed effects predictor, perform extremely poorly: the incorrect flagging rates are either unacceptably high (approaching 0.5 in the limit) or overly conservative (eg, much <0.05 for reasonable parameter values, leading to very low correct flagging rates). We develop novel methods for flagging extreme clusters that can control the incorrect flagging rates, including very simple-to-use versions that we call "self-calibrated." The new methods have substantially higher correct flagging rates than previously proposed methods for flagging extreme values, while controlling the incorrect flagging rates. We illustrate their application using data on length of stay in pediatric hospitals for children admitted for asthma diagnoses.

Lithospheric delamination as the driving mechanism of intermediate-depth seismicity in the Bucaramanga Nest, Colombia

The Bucaramanga nest (BN) is an area of exceptionally strong intermediate-depth seismicity localized in a narrow zone at 150–170 km depth beneath the continental plate in Colombia. To explain the very unusual mantle seismicity cluster in this area, we built a seismic velocity model in the vicinity of BN with the use of local earthquake tomography and developed a numerical hydromechanical model. Our seismic model shows a strong high-velocity anomaly at 130–167 km coinciding with the BN seismicity. The relocated seismicity can be separated in two clusters. We propose that the upper BN cluster at ~ 130 km depth is attributed to dehydration embrittlement, whereas the lower BN cluster at ~ 150 km depth coinciding with the high-velocity body is caused by lithospheric delamination, creating a “drip” that falls down over the subducting oceanic plate, enhancing fluid release from the slab, potentially increasing seismicity.

Investigation of an unusual cluster of illness among staff at a wildlife rescue centre

Abstract When two previously fit and well staff from a wildlife rescue centre were hospitalised in early September 2018 with severe pneumonia and meningitis symptoms, the Health Protection Team began an investigation. Possible diagnoses included influenza and legionella, although it was not flu season, and initial testing proved negative. There were reports of other staff illness over the preceding weeks. The centre had accepted a wide range species over the Summer, including high numbers of gulls and pigeons, and an outbreak of psittacosis was suspected; the patients responded rapidly to doxycycline. An incident management team was rapidly convened to investigate and determine control measures. A testing algorithm was developed: including for Influenza A&amp;B, Urine legionella &amp; pneumococcal antigen; reference laboratory serology testing and real-time PCR for Chlamydia.psittaci; and pan-corona viruses. Case finding was conducted by telephone interviews and a select-survey of all 55 staff gained 46 responses. A series of site visits examined working practices at the site. Avian and environmental sampling was undertaken. A total of 22 staff met the agreed case definition for psittacosis, five of whom were later confirmed. Clinical features ranged from mild to severe. The onset dates of illness ranged from July to September. There was no evidence of person-to-person transmission. Analysis did not show a clear correlation between PPE use and illness. Clinical, microbiological, environmental, veterinary, and epidemiological evidence indicated zoonotic transmission of psittacosis. Variable compliance with PPE, hygiene when handling birds, and disinfection had likely contributed via aerosolization of dust. This was likely exacerbated by very high bird stocks and unusually warm weather conditions. Comprehensive recommendations were made to reduce the chances of future outbreaks, which are generalisable to other countries. Key messages • This was one of the largest clusters of human psittacosis described in a workplace in England. • Biosecurity in animal rescue centres is crucial to limit the chance of psittacosis and other zoonoses.

Two Satellite Gene Clusters Enhance Ergot Alkaloid Biosynthesis Capacity of Aspergillus leporis.

Ergot alkaloids are fungal specialized metabolites that are important in agriculture and serve as sources of several pharmaceuticals. Aspergillus leporis is a soil saprotroph that possesses two ergot alkaloid biosynthetic gene clusters encoding lysergic acid amide production. We identified two additional, partial biosynthetic gene clusters within the A. leporis genome containing some of the ergot alkaloid synthesis (eas) genes required to make two groups of clavine ergot alkaloids, fumigaclavines and rugulovasines. Clavines possess unique biological properties compared to lysergic acid derivatives. Bioinformatic analyses indicated the fumigaclavine cluster contained functional copies of easA, easG, easD, easM, and easN. Genes resembling easQ and easH, which are required for rugulovasine production, were identified in a separate gene cluster. The pathways encoded by these partial, or satellite, clusters would require intermediates from the previously described lysergic acid amide pathway to synthesize a product. Chemical analyses of A. leporis cultures revealed the presence of fumigaclavine A. However, rugulovasine was only detected in a single sample, prompting a heterologous expression approach to confirm functionality of easQ and easH. An easA knockout strain of Metarhizium brunneum, which accumulates the rugulovasine precursor chanoclavine-I aldehyde, was chosen as expression host. Strains of M. brunneum expressing easQ and easH from A. leporis accumulated rugulovasine as demonstrated through mass spectrometry analysis. These data indicate that A. leporis is exceptional among fungi in having the capacity to synthesize products from three branches of the ergot alkaloid pathway and for utilizing an unusual satellite cluster approach to achieve that outcome. IMPORTANCE Ergot alkaloids are chemicals produced by several species of fungi and are notable for their impacts on agriculture and medicine. The ability to make ergot alkaloids is typically encoded by a clustered set of genes that are physically adjacent on a chromosome. Different ergot alkaloid classes are formed via branching of a complex pathway that begins with a core set of the same five genes. Most ergot alkaloid-producing fungi have a single cluster of genes that is complete, or self-sufficient, and produce ergot alkaloids from one or occasionally two branches from that single cluster. Our data show that Aspergillus leporis is exceptional in having the genetic capacity to make products from three pathway branches. Moreover, it uses a satellite cluster approach, in which gene products of partial clusters rely on supplementation with a chemical intermediate produced via another gene cluster, to diversify its biosynthetic potential without duplicating all the steps.

Ortho Effects of Tricarboxylate Linkers in Regulating Topologies of Rare-Earth Metal-Organic Frameworks.

A linker design strategy is developed to attain novel polynuclear rare-earth (RE) metal-organic frameworks (MOFs) with unprecedented topologies. We uncover the critical role of ortho-functionalized tricarboxylate ligands in directing the construction of highly connected RE MOFs. The acidity and conformation of the tricarboxylate linkers were altered by substituting with diverse functional groups at the ortho position of the carboxyl groups. For instance, the acidity difference between carboxylate moieties resulted in forming three hexanuclear RE MOFs with novel (3,3,3,10,10)-c wxl, (3,12)-c gmx, and (3,3,3,12)-c joe topologies, respectively. In addition, when a bulky methyl group was introduced, the incompatibility between the net topology and ligand conformation guided the co-appearance of hexanuclear and tetranuclear clusters, generating a novel 3-periodic MOF with a (3,3,8,10)-c kyw net. Interestingly, a fluoro-functionalized linker prompted the formation of two unusual trinuclear clusters and produced a MOF with a fascinating (3,8,10)-c lfg topology, which could be gradually replaced by a more stable tetranuclear MOF with a new (3,12)-c lee topology with extended reaction time. This work enriches the polynuclear clusters library of RE MOFs and unveils new opportunities to construct MOFs with unprecedented structural complexity and vast application potential.

Bismuth-Based Metal Clusters─From Molecular Aesthetics to Contemporary Materials Science.

ConspectusBismuth-based research has become a highly topical field in recent years, yielding remarkable prospects for new fundamental insights and new materials applications, ranging from innovative catalysts to novel pharmaceuticals, due to this heavy metal's virtually nonradioactive and nontoxic properties. Given that the 6s2 electron pair can be stereochemically active under certain circumstances, bismuth atoms adopt a variety of coordination modes and bonding environments with oxidation states ranging from (formally) +V to -III. As a consequence, bismuth-based compounds cover the entire spectrum from simple coordination compounds to much more unusual cluster cations and cluster anions exhibiting metal-metal bonding in a homoatomic manner, or in concert with other s-, d-, p-, or f-block metal atoms. Such bismuth clusters show high potential for the development of new bismuth-based materials, but they are also interesting objects by themselves. Given the relatively recent development of bismuth-rich cluster molecules, a deep understanding of their properties─including unprecedented structural features, complex electronic structures, substantial heavy metal aromaticity, as well as their formation pathways─is still in its infancy. The topic thus spans a broad range from highly sophisticated synthetic chemistry through interdisciplinary experimental and theoretical analyses to materials science.Based on our recent work and several notable reports from other groups, this article will highlight the successful access to a number of novel bismuth-rich cluster ions emerging from both solution-based approaches and solid-state chemistry. It will shed light on the unique structural and electronic properties that cause chemical and physical peculiarities of such compounds. Selected examples include, but are not limited to, (1) the first encapsulation of actinide ions in intermetalloid clusters which additionally served to manifest substantial all-metal π-aromaticity with a (calculated) record ring current per electron; (2) a large metalloid {Zn12} unit stabilized in a porphine-related {Zn8Bi16} moiety in [K2Zn20Bi16]6-; (3) the largest assembly of bismuth atoms within one molecule, observed in [{Ru(cod)}4Bi18]4- that consists of two Bi-Bi-linked "[{Ru(cod)}2Bi9]2-" subunits.Notably, cluster growth has remained largely a black box, which is starting to be revealed, however. We discuss possible formation pathways of such (multi)metallic nanoarchitectures on the basis of smaller subunits that were detected by mass spectrometric analyses and could also be captured upon reaction with organometallic complexes. In addition to the intrinsic structural and electronic properties of the cluster anions and cluster cations reviewed herein, we will briefly introduce the emerging usage of bismuth-based compounds in material science and give an outlook to future developments.

Subacute myoclonic measles encephalitis - An opportunistic HIV-associated infection.

An unusual cluster of myoclonic epilepsy was observed in a Romanian pediatric HIV cohort concurrent with measles outbreaks. We describe this particular form of subacute measles encephalitis (SME) in a group of HIV-infected children and adolescents with severe immunosuppression. This is a single-center study, starting in 1997 and covering 4 measles outbreaks in Romania. The presumptive diagnosis of subacute myoclonic measles encephalitis (SMME) was based on: (1) epidemiological data, previous measles episode or presumed contact with measles virus (MV), (2) clinical presentation with initial localized myoclonic jerks with rapid extension and subsequent motor deficit with preserved mental status, and (3) neuroimaging studies revealing cortical gray matter lesions. Definitive diagnosis was based on a neuropathological exam and immunohistochemistry of brain tissues, and measles RNA detection in the cerebrospinal fluid (CSF). Thirty-six patients were diagnosed with a particular form of SME during consecutive measles outbreaks in Romania: 1996-1998 (22); 2005-2008 (12); 2010-2011 (1) and 2016-2018 (1). Most children were born in the late 80s and had parenterally acquired HIV infection in early childhood. Before the episode of SMME, 11 patients had confirmed measles, while the rest, without typical rash, had a respiratory tract infection and/or presumed previous measles contact. In all patients, the clinical onset was sudden, with unilateral myoclonus. MRI findings revealed mainly focal cortical gray matter lesions. Neurologic symptoms progressed rapidly to coma and death in most patients. Three patients survived SMME, they had higher CD4 count at onset, slower progression of neurological symptoms, and benefit of immune recovery with cART. Immunocytochemistry studies revealed MV in the brain with a pattern suggesting an ascending viral neural infection. MV was isolated from CSF in 7 out of 8 patients. Sequence analysis of MV RNA from both nasopharyngeal swabs and CSF was available for one patient with similar N-450 strain characteristics. During an outbreak of measles, neurological manifestations, especially myoclonus in immunosuppressed patients, can be related to measles even in the absence of an acute episode. This particular form of subacute myoclonic measles encephalitis is an opportunistic fatal disease. Immune recovery due to effective antiretroviral treatment might increase survival.

An unusual refuge: A case study of a South Asian and African multi-ethnic cluster in a Hong Kong rural walled village

This article explores an unusual multi-ethnic cluster in a walled village in rural Hong Kong. Once known for its exclusivity, the village, located in the New Territories, now houses hundreds of ethnic minority migrants, of whom one-third are South Asian and African. The article draws on 30 months of fieldwork between 2008 and 2011 and subsequent fieldwork in 2019–2020, including in-depth interviews with migrants and indigenous villagers in one walled village, to investigate the nature of these multi-ethnic clusters. The author critically examines the extent to which prevalent theories of ethnic clustering can be applied to the emerging phenomenon of growing multi-ethnic clusters in this rural part of Hong Kong. By examining the form and factors contributing to cluster formation, the author argues that the demographic characteristics, location, and constitution of such formations are not entirely consistent with existing studies in the West. Theories of the development of multi-ethnic clusters should therefore take into account their particular political, historical, and cultural context, as well as the socioeconomic characteristics of the location.

Novel and unusual genes for nitrogen and metal cycling in Planctomycetota- and KSB1-affiliated metagenome-assembled genomes reconstructed from a marine subsea tunnel.

The Oslofjord subsea road tunnel is a unique environment in which the typically anoxic marine deep subsurface is exposed to oxygen. Concrete biodeterioration and steel corrosion in the tunnel have been linked to the growth of iron- and manganese-oxidizing biofilms in areas of saline water seepage. Surprisingly, previous 16S rRNA gene surveys of biofilm samples revealed microbial communities dominated by sequences affiliated with nitrogen-cycling microorganisms. This study aimed to identify microbial genomes with metabolic potential for novel nitrogen- and metal-cycling reactions, representing biofilm microorganisms that could link these cycles and play a role in concrete biodeterioration. We reconstructed 33 abundant, novel metagenome-assembled genomes (MAGs) affiliated with the phylum Planctomycetota and the candidate phylum KSB1. We identified novel and unusual genes and gene clusters in these MAGs related to anaerobic ammonium oxidation, nitrite oxidation, and other nitrogen-cycling reactions. Additionally, 26 of 33 MAGs also had the potential for iron, manganese, and arsenite cycling, suggesting that bacteria represented by these genomes might couple these reactions. Our results expand the diversity of microorganisms putatively involved in nitrogen and metal cycling, and contribute to our understanding of potential biofilm impacts on built infrastructure.

Pore Environment Optimization of Microporous Metal–Organic Frameworks with Huddled Pyrazine Pillars for C2H2/CO2 Separation

Metal-organic frameworks (MOFs) have been proven promising in addressing many critical issues related to gas separation and purification. However, it remains a great challenge to optimize the pore environment of MOFs for purification of specific gas mixtures. Herein, we report the rational construction of three isostructural microporous MOFs with the 4,4',4"-tricarboxyltriphenylamine (H3TCA) ligand, unusual hexaprismane Ni6O6 cluster, and functionalized pyrazine pillars [PYZ-x, x = -H (DZU-10), -NH2 (DZU-11), and -OH (DZU-12)], where the building blocks of Ni6O6 clusters and huddled pyrazine pillars are reported in porous MOFs for the first time. These building blocks have enabled the resulting materials to exhibit good chemical stability and variable pore chemistry, which thus contribute to distinct performances toward C2H2/CO2 separation. Both single-component isotherms and dynamic column breakthrough experiments demonstrate that DZU-11 with the PYZ-NH2 pillar outperforms its hydrogen and hydroxy analogues. Density functional theory calculations reveal that the higher C2H2 affinity of DZU-11 over CO2 is attributed to multiple electrostatic interactions between C2H2 and the framework, including strong C≡C···H-N (2.80 Å) interactions. This work highlights the potential of pore environment optimization to construct smart MOF adsorbents for some challenging gas separations.

Ga@Bi10(NbMes)2]3-: a linear Nb-GaI-Nb filament coordinated by a bismuth cage.

In this work, we report a low-valent Ga(I) complex, [Ga@Bi10(NbMes)2]3-, with a linear Nb-Ga-Nb fragment, representing the first compound with Nb-Ga and Nb-Bi bonds. Quantum-chemical calculations reveal that the complex is an electron-precise cluster. The possible fragmentation pathway of the title cluster was studied by using electrospray ionization mass spectrometry and theoretical calculations.

Diversity, duplication, and genomic organization of homeobox genes in Lepidoptera.

Homeobox genes encode transcription factors with essential roles in patterning and cell fate in developing animal embryos. Many homeobox genes, including Hox and NK genes, are arranged in gene clusters, a feature likely related to transcriptional control. Sparse taxon sampling and fragmentary genome assemblies mean that little is known about the dynamics of homeobox gene evolution across Lepidoptera or about how changes in homeobox gene number and organization relate to diversity in this large order of insects. Here we analyze an extensive data set of high-quality genomes to characterize the number and organization of all homeobox genes in 123 species of Lepidoptera from 23 taxonomic families. We find most Lepidoptera have around 100 homeobox loci, including an unusual Hox gene cluster in which the lab gene is repositioned and the ro gene is next to pb A topologically associating domain spans much of the gene cluster, suggesting deep regulatory conservation of the Hox cluster arrangement in this insect order. Most Lepidoptera have four Shx genes, divergent zen-derived loci, but these loci underwent dramatic duplication in several lineages, with some moths having over 165 homeobox loci in the Hox gene cluster; this expansion is associated with local LINE element density. In contrast, the NK gene cluster content is more stable, although there are differences in organization compared with other insects, as well as major rearrangements within butterflies. Our analysis represents the first description of homeobox gene content across the order Lepidoptera, exemplifying the potential of newly generated genome assemblies for understanding genome and gene family evolution.

Polynuclear ruthenium clusters containing stibine, stibene, and stibinidene ligands

The reaction of [Ru3(CO)10(µ-dppm)] with SbPh3 has been investigated. Me3NO activation of [Ru3(CO)10(µ-dppm)] in the presence of excess SbPh3 yields the known cluster [Ru3(CO)9(SbPh3)(μ-dppm)] (1) in nearly quantitative yield. Refluxing 1 in THF yields the new triruthenium clusters [Ru3(CO)8{μ,η2-C(O)Ph}(µ-SbPh2)(µ-dppm)] (2) and [Ru3(CO)9(σ-C6H5)(μ-SbPh2)(µ-dppm)] (3). Both clusters exhibit an opened Ru3 polyhedron supported by a bridging stibene ligand (SbPh2), whose formation results from the cleavage of an Sb–Ph bond of the SbPh3 ligand in 1. Cluster 2 contains a μ,η2-C(O)Ph ligand formed by the coupling of the cleaved Ph moiety with a coordinated CO ligand. In contrast, cluster 3 contains a σ-bonded phenyl moiety that is situated trans to the μ-SbPh2 moiety. Thermolysis of [Ru3(CO)10(µ-dppm)] with SbPh3 at 80°C furnished the new cluster [Ru3(CO)7(σ-C6H5)(μ-SbPh2)2{μ-C(=O)C6H4P(Ph)CH2PPh2}] (4) as the major product, along with 2 and 3. Control experiments involving 2 and excess SbPh3 at 80°C afforded 4. In contrast, the reaction between [Ru3(CO)10(µ-dppm)] and SbPh3 at 110°C furnished the unusual Ru6Sb2 cluster [Ru6(CO)13(μ-CO)(μ-SbPh2)(μ4-SbPh){μ-C(=O)C6H4P(Ph)CH2PPh2}(μ-dppm)] (5) in addition to 2. The results of thermal control experiments demonstrating the conversion of 1 to 5 are discussed. The molecular structures of 2–5 have been established by X-ray crystallography, and the bonding in these new clusters has been examined by electronic structure calculations.

An Anomaly Detection Framework for Twitter Data

An anomaly indicates something unusual, related to detecting a sudden behavior change, and is also helpful in detecting irregular and malicious behavior. Anomaly detection identifies unusual events, suspicious objects, or observations that differ significantly from normal behavior or patterns. Discrepancies in data can be observed in different ways, such as outliers, standard deviation, and noise. Anomaly detection helps us understand the emergence of specific diseases based on health-related tweets. This paper aims to analyze tweets to detect the unusual emergence of healthcare-related tweets, especially pre-COVID-19 and during COVID-19. After pre-processing, this work collected more than 44 thousand tweets and performed topic modeling. Non-negative matrix factorization (NMF) and latent Dirichlet allocation (LDA) were deployed for topic modeling, and a query set was designed based on resultant topics. This query set was used for anomaly detection using a sentence transformer. K-means was also employed for clustering outlier tweets from the cleaned tweets based on similarity. Finally, an unusual cluster was selected to identify pandemic-like healthcare emergencies. Experimental results show that the proposed framework can detect a sudden rise of unusual tweets unrelated to regular tweets. The new framework was employed in two case studies for anomaly detection and performed with 78.57% and 70.19% accuracy.

Variably rotated lamproite dikes within a transpressive fault zone: Structural and paleomagnetic analysis of the Socovos Fault zone (Eastern Betics, SE Spain)

Rotations of large-scale crustal blocks deduced from paleomagnetism are usually invoked to support evolutionary tectonic models in orogens. However, the regional representativeness of local paleomagnetic rotations strongly depends on the structural context and can lead to conflicting results. This work analyzes an unusual cluster of almost coeval lamproite dikes (9.3–7.1 Ma) intruded along a 25 km-long segment of the Socovos transpressive fault zone in the Eastern Betics, with a view to determine rotations at the metre-scale. This fault zone has contrasting deformation styles, depending on the rheology of the rocks, which vary from ductile evaporites (gypsum) to brittle carbonates. The volcanic and subvolcanic rocks present a primary acquisition of high quality natural remanent magnetization, which defines a single directional component with very narrow α95. Matching the outcrop scale structures with the apparently dispersed paleomagnetic directions in the fault zone allows us to differentiate four deformational domains with distinctive characteristics: (1) a brittle zone with deformation concentrated in planes that bound blocks with no rotation or rotations below the expected secular variation ( ± 16° in inclination and ± 21° declination); (2) transpressive decametre-scale duplexes or single horses, also limited by brittle faults, where inclined axis rotations below 60° occur as rigid blocks; (3) buckling folds in ductile units associated with local reverse faulting; and (4), a triclinic transpressive ductile shear zone affecting a gypsum layer, where volcanic boudins have a rotation that is the sum of folding parallel to the shear zone walls plus an angular shear of 36°. These paleomagnetic results indicate that fault displacement continues after 7 Ma with the same kinematics as previously. Besides regional findings, this study illustrates the potential usefulness of small-scale paleomagnetic analysis for determining strain partitioning and deformation mode along large and complex transpressive fault zones, as well as the necessity to know the local structure to attribute regional meaning to the paleomagnetic rotation data.

Low-density star cluster formation: discovery of a young faint fuzzy on the outskirts of the low-mass spiral galaxy NGC 247

ABSTRACT The classical globular clusters found in all galaxy types have half-light radii of rh ∼ 2–4 pc, which have been tied to formation in the dense cores of giant molecular clouds. Some old star clusters have larger sizes, and it is unclear if these represent a fundamentally different mode of low-density star cluster formation. We report the discovery of a rare, young ‘faint fuzzy’ star cluster, NGC 247-SC1, on the outskirts of the low-mass spiral galaxy NGC 247 in the nearby Sculptor group, and measure its radial velocity using Keck spectroscopy. We use Hubble Space Telescope imaging to measure the cluster half-light radius of rh ≃ 12 pc and a luminosity of LV ≃ 4 × 105L⊙. We produce a colour–magnitude diagram of cluster stars and compare to theoretical isochrones, finding an age of ≃300 Myr, a metallicity of [Z/H] ∼ −0.6 and an inferred mass of M⋆ ≃ 9 × 104M⊙. The narrow width of blue-loop star magnitudes implies an age spread of ≲50 Myr, while no old red-giant branch stars are found, so SC1 is consistent with hosting a single stellar population, modulo several unexplained bright ‘red straggler’ stars. SC1 appears to be surrounded by tidal debris, at the end of an ∼2 kpc long stellar filament that also hosts two low-mass, low-density clusters of a similar age. We explore a link between the formation of these unusual clusters and an external perturbation of their host galaxy, illuminating a possible channel by which some clusters are born with large sizes.

Synthesis and structure of metal-TCPE (metal = Th, Ce) metal-organic frameworks based on 1,2,4,5-tetrakis(4-carboxyphenyl) ethylene.

Two new metal-organic frameworks (MOFs) (Th/ Ce -TCPE) based on 1,2,4,5-tetrakis(4-carboxyphenyl)ethylene were obtained using a straightforward reaction under moderate conditions. Th and Ce formed the central units of this MOF in the mononuclear and in the unusual trinuclear cluster configurations, respectively. The resulting MOFs were analysed by fluorescence spectroscopy to understand their luminescence. The obtained data revealed that benzene's electron cloud density and torsion angle on the ligand were affected by the acetic acid molecule and Th(IV), which caused Th-TCPE to irradiate stronger blue emission, but Ce-TCPE showed no fluorescence due to the self-quenching. Such a unique luminescence property could be used for fluorescence or radiopharmaceutical sensing.

Genetic suppressors of Δgrx3 Δgrx4, lacking redundant multidomain monothiol yeast glutaredoxins, rescue growth and iron homeostasis.

Saccharomyces cerevisiae Grx3 and Grx4 are multidomain monothiol glutaredoxins that are redundant with each other. They can be efficiently complemented by heterologous expression of their mammalian ortholog, PICOT, which has been linked to tumor development and embryogenesis. PICOT is now believed to act as a chaperone distributing Fe-S clusters, although the first link to iron metabolism was observed with its yeast counterparts. Like PICOT, yeast Grx3 and Grx4 reside in the cytosol and nucleus where they form unusual Fe-S clusters coordinated by two glutaredoxins with CGFS motifs and two molecules of glutathione. Depletion or deletion of Grx3/Grx4 leads to functional impairment of virtually all cellular iron-dependent processes and loss of cell viability, thus making these genes the most upstream components of the iron utilization system. Nevertheless, the Δgrx3/4 double mutant in the BY4741 genetic background is viable and exhibits slow but stable growth under hypoxic conditions. Upon exposure to air, growth of the double deletion strain ceases, and suppressor mutants appear. Adopting a high copy-number library screen approach, we discovered novel genetic interactions: overexpression of ESL1, ESL2, SOK1, SFP1 or BDF2 partially rescues growth and iron utilization defects of Δgrx3/4. This genetic escape from the requirement for Grx3/Grx4 has not been previously described. Our study shows that even a far-upstream component of the iron regulatory machinery (Grx3/4) can be bypassed, and cellular networks involving RIM101 pH sensing, cAMP signaling, mTOR nutritional signaling, or bromodomain acetylation, may confer the bypassing activities.

An unusual cluster of Waugh syndrome as a cause of intestinal obstruction in children - A case series.

Introduction and importanceThe association of intussusception with intestinal malrotation is a rare phenomenon named Waugh syndrome by Brereton et. It is a rare disease entity with less than 100 cases described so far. A cluster presentation is something unusual for rare diseases.Case presentationAll four patients have presented with features suggestive of bowel obstruction as all of them have had colicky abdominal pain. Three patients have vomiting as an additional complaint, so as the diarrhea. Fever has also been reported in one patient. Patients have presented in 6 months period, non-consecutively. Abdominal pain, diarrhea and vomiting are alarming in the pediatric population. When each case presented, an immediate resuscitation was performed including IV lines, nasogastric suctioning, electrolytes correction, and blood and FFP transfusion as necessary. Abdominal ultrasonography was performed revealing target sign. After optimization for surgery, manual reduction of the intussusception was done followed by a Ladd's procedure for the malrotation was performed for all 4 patients with excellent outcomes.Clinical discussionWith the surgery, after case optimization, remains the standard of care; the presence of cluster presentation for Waugh syndrome could suggest that some environmental factors might be implicated and further observations can be carried out to look more into such phenomenon.ConclusionWaugh syndrome, a combined presentation of intestinal malrotation and intussusception, is a rare syndrome that can present in children. Optimization for surgery followed by a 2-step surgical approach is the usual treatment with excellent outcomes described.