Poly[di-μ3-chlorido-[μ2-(3-pyrid­yl)(4-pyrid­yl)methanone-κ2 N:N′]dicopper(I)]

In the title compound, [Cu2Cl2(C11H8N2O)]n, stair-like ribbons of formula [Cu2Cl2]n are linked into coordination polymer layers by tethering (3-pyrid­yl)(4-pyrid­yl)methanone (3,4′-dpk) ligands. The two distinct CuI centres both adopt distorted CuNCl3 tetra­hedral coordinations. Individual [Cu2Cl2(3,4′-dpk)]n layers stack in an AB pattern along the c direction by way of weak C—H⋯O inter­actions between the pyridyl rings and ketone O atoms

4-(4-Pyridylamino)pyridinium perchlorate

In the title salt, C10H10N3 +·ClO4 −, the 4-(4-pyridylamino)­pyridinium cations are linked into chains via N—H⋯N hydrogen bonding and into layers by C—H⋯π inter­actions [C⋯Cg = 3.3875 (19) Å]. Perchlorate ions are anchored to the layer motifs by N—H⋯O hydrogen bonding. The perchlorate anion was found to be disordered about a Cl—O axis, with two sites, each of equal occupancy, being resolved for the three remaining O atoms

Bis(dimethyl­malonato-κ2 O,O′)bis­[4-(4-pyridylamino-κN 4)pyridinium]nickel(II) hexa­hydrate

In the title compound, [Ni(C5H6O4)2(C10H10N3)2]·6H2O, divalent nickel ions situated on the crystallographic twofold axis are octa­hedrally coordinated by four O atoms from two dimethyl­malonate ligands in a 1,3-chelating mode and two N atoms from two protonated monodentate 4,4′-dipyridylamine mol­ecules. The mol­ecules link into chains via N—H⋯O hydrogen bonding mediated by protonated pyridyl groups. The chains form layer patterns via π–π stacking [centroid–centroid distance = 3.777 (2) Å] . Water mol­ecule hexa­mers are generated from the unligated water mol­ecules (three per asymmetric unit) by inversion centers at Wyckoff position d. These clusters are situated between the pseudolayers, providing hydrogen-bonding pathways that build up the three-dimensional structure

4,4′-Imino­dipyridinium bis­(hydrogen phthalate)

In the title salt, C10H11N3 2+·2C8H5O4 −, doubly protonated 4,4′-dipyridylamine (dpa) cations participate in N—H⋯O hydrogen bonding with two hydrogen phthalate anions to form a neutral unit. Both anions contain an intramolecular O—H⋯O hydrogen bond. In the crystal structure, these units form two-dimensional layers through π–π stacking inter­actions with a centroid-to-centroid distance of 3.763 (3) Å. In turn, these layers aggregate in three dimensions by additional N—H⋯O hydrogen bonding. The assignment to the noncentrosymmetric space group P1 is corroborated by chemically unreasonable aromatic ring bond distances and poor K scale factor distributions for a disordered model in the centrosymmetric P space group

Bis(2,2′-bipyridine-κ2 N,N′)(maleato-κ2 O 1,O 1′)nickel(II) 7.34-hydrate

The title compound, [Ni(C4H2O4)(C10H8N2)2]·7.34H2O, was obtained by crystallization from an aqueous ethano­lic reaction mixture containing nickel(II) acetate, maleic acid, bipyridine, sodium hydroxide and ammonia. The asymmetric unit contains one independent complex mol­ecule and 7.34 water mol­ecules occupying eight crystallographically independent positions. Two of these water molecules are disordered. The nickel(II) atom is coordinated in a distorted octa­hedral geometry by two O atoms from one carboxyl­ate group of the maleato ligand and by four N atoms from two 2,2′-bipyridine (bipy) ligands. The water mol­ecules, along with the O atoms of the uncoordinated carboxyl­ate group, form an extended hydro­philic three-dimensional hydrogen-bonded system with large cavities in which the hydro­phobic bipy ligands are located. One H atom of the maleate ligand is involved in a weak hydrogen bond of the C—H⋯O type. Stacking inter­actions between the pyridyl rings of the bipy ligands [centroid–centroid distance = 3.549 (15) Å] lead to the formation of pairs of complex mol­ecules

Using guinea pig models to examine the relation between psychophysical and neural responses to electrical stimulation of cochlear implants.

Animal models are used to study the physiology underlying cochlear implant function. In these models, various treatment protocols are used in attempts to represent the conditions of deafness in implanted patients. These protocols are known to affect psychophysical detection threshold levels and are likely to affect physiological data as well. This variation in methodology might affect the conclusions drawn from the neural data about the mechanisms underlying auditory perception. The purpose of this dissertation was to determine how the neural data were affected by treatment protocol. Data were collected from groups of animals using various treatment procedures, which included acute, short-term, and long-term deafening groups. One group underwent psychophysical testing in addition to physiological recording. Multiunit activity was recorded along the tonotopic axis of the inferior colliculus (IC). Strength-duration functions and spatial tuning curves (STC) were determined for bipolar (BP) and monopolar (MP) stimulation. Threshold levels were strongly affected by the treatment protocol. However, the slopes of the strength-duration functions and the STC widths did not differ systematically across treatment groups. Neural thresholds collected from the short-term deafened groups were generally higher and more variable than those collected for the long-term deafened groups. Neural thresholds for the psychophysically trained animals were lowest. Thresholds for BP stimulation showed more variance across all groups than thresholds for MP stimulation. Electrode configuration affected the psychophysical strength-duration-function slopes, but did not affect the neural strength-duration function slopes. Implant insertion methods had large and unexpected effects on psychophysical and neural thresholds. Of the groups tested, the psychophysically-tested group seemed to be best for studying mechanisms of psychophysical stimulus detection because the neural thresholds were closest to the psychophysical thresholds obtained from these same animals. In addition, because of the wide variability of thresholds observed in the acutely-tested groups, these groups might be good animal models for study of functionally relevant anatomical and physiological changes in the cochlea following deafening and/or implantation. Data from this study and future studies will be helpful in interpreting differences in thresholds observed across patients and across stimulation sites, as well as threshold changes over time.Ph.D.Biological SciencesNeurosciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/126078/2/3016919.pd

Speech Perception in Children with and Without Speech Sound Disorders Who Articulate /ɹ/ as [w]

The purpose of this study was to investigate the speech perception skills for one sound contrast neutralized in 4- to 6-year-olds with Speech Sound Disorders (SSD) and 3- to 5-year-olds with Typical Development (TD), all of whom produce /ɹ/ and /w/ as [w]. Using a Looking-While-Listening (LWL) paradigm, participants’ looking patterns to correctly produced (CP) and mispronounced (MP) trials were analyzed. Results showed that children with SSD demonstrated above chance looking to the target for MP experimental trials but not for CP trials. In contrast, the younger children with TD demonstrated above chance looking to the target for CP experimental trials but not MP trials. These results suggest that children with SSD do not have the same phonological representations as their younger peers with TD who produce the same speech error, suggesting a clear difference between the groups based on diagnosis. Additionally, children with SSD showed above chance performance and no difference in looking for CP and MP foil trials. This performance pattern is distinct from that seen in monodialectal children, but is similar to that seen in multidialectal children. Thus, I argue that this difference may be explained by the fact that their own idiolect (/ɹ/ and /w/ produced as [w]) coupled with the majority dialect (/ɹ/ produced as [ɹ]) results in a multidialectal input

Effects of Sedentary Behavior Interventions on Mental Well-Being and Work Performance While Working from Home during the COVID-19 Pandemic: A Pilot Randomized Controlled Trial

Sedentary behavior negatively impacts mental health, which can decrease employee productivity. Employee mental well-being and work performance may improve with sedentary reduction interventions, especially strategies that include environmental workplace modifications and behavior-changing strategies. However, such interventions have not been examined among employees working remotely during the COVID-19 pandemic. As part of the Stand Up Kansas program, 95 sedentary university employees working from home were randomized into one of four intervention arms: height-adjustable desk provision (Desk Only), online sedentary behavior modification program (Program Only), Desk + Program, or Control. The outcomes were measured at a baseline (November 2020) and following the 12-week intervention (February 2021). Employees reported mood (positive and negative affect), stress, fatigue (duration, interference with activities and severity) and work performance (irritability, focus, work satisfaction, non-work satisfaction and productivity) were measured using established self-report instruments. The effect sizes, by comparing the Control arm to the Desk + Program arm, revealed large improvements in mood (positive affect, d = 1.106). Moderate improvements were also seen in fatigue (duration, d = −0.533, and interference with activities, d = −0.648) and several aspects of work performance (focus, d = 0.702, work satisfaction, d = 0.751, and productivity, d = 0.572). Moderate effect sizes were also seen for positive affect (d = 0.566) and fatigue severity (d = 0.577) among the Program Only arm, whereas no noteworthy effect sizes were observed among the Desk Only arm. Combining an online sedentary behavior modification program with height-adjustable desk provisions appeared to positively affect mental well-being and work performance among remote employees