Management of Post Dural Puncture Headache During Spinal Cord Stimulation Trials: A Review of Current Literature.

PURPOSE OF REVIEW: The purpose of this review is to evaluate, discuss and explain the current literature regarding management of post dural puncture headaches (PDPH) during spinal cord stimulation (SCS) trials. RECENT FINDINGS: Although an epidural blood patch (EBP) remains the gold standard in treatment of PDPH, current literature describes other modalities including various peripheral nerve blocks and pharmacological treatments to reduce PDPH symptoms. PDPH management in SCS centers around conservative treatment and EBP. It has been shown that some practitioners choose prophylactic measures and/or an EBP at the time of the lead placement. Recent literature regarding obstetric anesthesia related PDPH management has included newer potential modalities for addressing symptom improvement that can also be applied to PDPH from SCS trial dural punctures. Due to limited data overall, further studies are needed to effectively provide a guideline on optimal treatment protocols for PDPH after dural puncture in SCS trials.

Common Salt versus Silver Nitrate for the Treatment of Umbilical Granuloma in Infants: An Open-label, Single-center, Pilot Randomized Controlled Trial.

Aim: This study aims to compare the efficacy and safety of topical application of common salt (CS) in comparison to silver nitrate (SN) for treating infants with umbilical granuloma (UG). Materials and Methods: We conducted an open-label, prospective, single-center, pilot randomized controlled trial. Thirty-seven infants with a clinical UG diagnosis were enrolled between October 2022 and July 2023, excluding those previously treated for UG. Patients were randomly assigned (using the Randomizer® app) to receive either topical CS (applied thrice daily by caregivers at home for 5 days) or SN (applied by pediatric surgeon in clinic and kept under occlusive dressing for 48 h). Patients with partial/no healing received an additional session of the same treatment. Nonresponders transitioned from CS to SN, and vice versa, for two more applications. Healing rates were compared with a significance level of α =0.05. Results: Out of 34 patients (18 CS and 16 SN), 32 successfully completed the trial (17 CS and 15 SN). No significant differences were observed in baseline characteristics. Efficacy rates of CS (19/22; 86.36%) and SN (11/17; 64.71%) did not significantly differ (P = 0.056; 95% confidence interval [CI] -0.4832-0.0502). No major adverse events were reported. CS showed superior healing outcomes in infants below 3 months of age (19/22; 86.36%) compared to SN (11/17; 64.71%) (P = 0.056; 95% CI - 0.4832-0.0502). The timing of umbilical cord detachment did not significantly affect healing rates. Conclusion: Widespread availability, ease of access, suitability for safe home application, and cost-effectiveness make CS a primary treatment option for UG. Larger patient cohorts are needed for conclusive results.

In Situ Imaging of Faujasite Surface Growth Reveals Unique Pathways of Zeolite Crystallization.

Zeolite crystallization occurs by complex processes involving a variety of possible mechanisms. The sol gel media used to prepare zeolites leads to heterogeneous mixtures of solution and solid states with diverse solute species. At later stages of zeolite synthesis when growth occurs predominantly from solution, classical two-dimensional nucleation and spreading of layers on crystal surfaces via the addition of soluble species is the dominant pathway. At earlier stages, these processes occur in parallel with nonclassical pathways involving crystallization by particle attachment (CPA). The relative roles of solution- and solid-state species in zeolite crystallization have been a subject of debate. Here, we investigate the growth mechanism of a commercially relevant zeolite, faujasite (FAU). In situ atomic force microscopy (AFM) measurements reveal that supernatant solutions extracted from a conventional FAU synthesis at various times do not result in growth, indicating that FAU growth predominantly occurs from the solid state through a disorder-to-order transition of amorphous precursors. Elemental analysis shows that supernatant solutions are significantly more siliceous than both the original growth mixture and the FAU zeolite product; however, in situ AFM studies using a dilute clear solution with a lower Si/Al ratio revealed three-dimensional growth of surfaces that is distinct from layer-by-layer and CPA pathways. This unique mechanism of growth differs from those observed in studies of other zeolites. Given that relatively few zeolite frameworks have been the subject of mechanistic investigation by in situ techniques, these observations of FAU crystallization raise the question whether its growth pathway is characteristic of other zeolite structures.

Catamenial epilepsy occurrence and patterns in a mixed population of women with epilepsy.

We evaluated the occurrence and distribution of patterns of catamenial epilepsy in a heterogenous cohort of women with epilepsy on no hormonal therapies, enrolled in a prospective, observational study. The primary aim of the study was pregnancy rate in women with epilepsy with no prior reproductive problems. In this analysis, we included women who recorded one or more menstrual cycles with one or more seizures. We measured progesterone concentrations for one to three cycles. We defined catamenial patterns as twofold or greater average daily seizure frequency around menstruation (C1), ovulation (C2), and for anovulatory cycles, from midcycle through menstruation (C3). Twenty-three of the 89 enrolled women with epilepsy were eligible for this analysis; 12 of 23 met criteria for catamenial epilepsy; five of 23 demonstrated only a C1 pattern, two of 23 only a C2 pattern, five of 23 a combined C1/C2 pattern, and the one woman with anovulatory cycles did not demonstrate a C3 pattern. There were no differences in likelihood of demonstrating a catamenial pattern between those who reported a prior catamenial pattern and those who did not (p = .855). This analysis demonstrates the utility of app-based tracking to determine a catamenial pattern. Larger prospective studies could confirm these findings and inform potential therapeutic trial designs for catamenial epilepsy.

In situ imaging of two-dimensional surface growth reveals the prevalence and role of defects in zeolite crystallization.

Zeolite crystallization predominantly occurs by nonclassical pathways involving the attachment of complex (alumino)silicate precursors to crystal surfaces, yet recurrent images of fully crystalline materials with layered surfaces are evidence of classical growth by molecule attachment. Here we use in situ atomic force microscopy to monitor three distinct mechanisms of two-dimensional (2D) growth of zeolite A where we show that layer nucleation from surface defects is the most common pathway. Direct observation of defects was made possible by the identification of conditions promoting layered growth, which correlates to the use of sodium as an inorganic structure-directing agent, whereas its replacement with an organic results in a nonclassical mode of growth that obscures 2D layers and markedly slows the rate of crystallization. In situ measurements of layered growth reveal that undissolved silica nanoparticles in the synthesis medium can incorporate into advancing steps on crystal surfaces to generate defects (i.e., amorphous silica occlusions) that largely go undetected in literature. Nanoparticle occlusion in natural and synthetic crystals is a topic of wide-ranging interest owing to its relevance in fields spanning from biomineralization to the rational design of functional nanocomposites. In this study, we provide unprecedented insight into zeolite surface growth by molecule addition through time-resolved microscopy that directly captures the occlusion of silica nanoparticles and highlights the prevalent role of defects in zeolite crystallization.

In situ healing of dendrites in a potassium metal battery.

The use of potassium (K) metal anodes could result in high-performance K-ion batteries that offer a sustainable and low-cost alternative to lithium (Li)-ion technology. However, formation of dendrites on such K-metal surfaces is inevitable, which prevents their utilization. Here, we report that K dendrites can be healed in situ in a K-metal battery. The healing is triggered by current-controlled, self-heating at the electrolyte/dendrite interface, which causes migration of surface atoms away from the dendrite tips, thereby smoothening the dendritic surface. We discover that this process is strikingly more efficient for K as compared to Li metal. We show that the reason for this is the far greater mobility of surface atoms in K relative to Li metal, which enables dendrite healing to take place at an order-of-magnitude lower current density. We demonstrate that the K-metal anode can be coupled with a potassium cobalt oxide cathode to achieve dendrite healing in a practical full-cell device.

Effects of Electron Beam Sterilization on Polytetrafluoroethylene: Design of Experiments Study.

Polytetrafluoroethylene (PTFE) is a common polymer used in medical devices due to its exceptional properties (e.g., biocompatibility, inertness, chemical stability, low coefficient of friction). However, as a result of molecular weight reduction caused by the process of chain scission, it is known to be susceptible to radiation exposure and can rapidly lose strength and integrity. In this design of experiments study, the goal was to determine whether an operating window of conditions exist for electron beam (E-beam) radiation sterilization in which the degradation of PTFE is acceptably low. PTFE was tested for yield stress after exposure to radiation under different parameters (total dose [15-60 kGy], packaging atmosphere [air/nitrogen], and poststerilization accelerated aging [real-time equivalent of 1 and 3 years]). The results showed that total dose and packaging atmosphere were significant factors and indicated that the use of modified atmosphere packaging (vacuum sealing with nitrogen gas purge) can be a useful approach in increasing the stability of PTFE toward E-beam sterilization.

Ingestion poisoning related lung injury- a pictorial review.

Poison ingestion is a medical emergency requiring immediate care in the emergency department. Respiratory symptoms with ingested poisons can occur due to aspiration, cardiopulmonary effects, or direct lung toxicity due to injury of the alveolar epithelium. Chest imaging (chest radiographs/CT) is usually performed in the emergency setting to evaluate such symptoms. It is often impossible to elicit the nature of the poison ingested by the patients due to their unconscious state. Identification of the culprit poison can expedite the patient's management towards a specific antidote or help understand the underlying mechanism causing the pulmonary symptoms. The imaging manifestations depend on the underlying mechanisms, varying for each ingested poison, forming an imaging signature which has not been adequately discussed in existing literature. Poisons like paraquat and organophosphate are important to differentiate as indiscriminate use of oxygen therapy in the former can exacerbate the lung injury caused by redox cycling. In this pictorial assay, we present the chest imaging spectrum of commonly ingested poisons, and further suggest algorithmic approach towards identification of common poisons based on their chest imaging.

A Study of Role of Ngal in Diagnosis and Staging the Severity of Diabetic Nephropathy in Type 2 Diabetes Mellitus Patients in Sms Medical College, Jaipur.

Present work was conducted to study of role of NGAL in diagnosis and staging the severity of diabetic nephropathy in type 2 diabetes mellitus patients to assess serum NGAL, urine albumin levels in diabetic patients with and without apparent nephropathy. MATERIAL: Comparative study conducted in the General Medicine department of SMS Hospital. INCLUSION CRITERIA: Patients of type 2 Diabetes mellitus. EXCLUSION CRITERIA: Patients consuming high protein diet, pregnancy, severe muscular exercises, orthostatic albuminuria, congestive heart failure, urinary tract infections, liver diseases. Patients with type 1 diabetes mellitus. OBSERVATION: The mean age of patient was 51.7 years. Here, HbA1c and NGAL were negatively correlated with each other with Pearson correlation -0.484 (p-value<0.05). In prediabetic patients mean NGAL was 407ng/ml and as HbA1c increases mean NGAL decreases 276.69 ng/ml (P-value <0.0012). As ACR increases mean NGAL increases significantly (P-value<0.05). CONCLUSION: Neutrophil gelatinase-associated lipocalin could be a renal function evaluation marker for patients with renal dysfunction and markers for detection of diabetic nephropathy in patients with type2 diabetes mellitus.

Obesity, Thyroid and OSA: An Intriguing Triangle.

The complex relationship between BMI, thyroid and its effects on OSA raises a question on how patients with suspected OSA should be evaluated. Some studies have described an association between thyroid disorders and OSA. Whether this is a direct effect of thyroid disorders, or it is indirectly related to BMI values is an important point to ponder. The aim of this study was to estimate the prevalence of thyroid disorders in relation to BMI in newly diagnosed patients with OSA (AHI > 5/h on diagnostic Polysomnography) at sleep lab of our tertiary care centre. In addition, we compared baseline characteristics of OSA patients with thyroid parameters. MATERIAL: In this hospital based observational study, recently diagnosed OSA on the basis of PSG showing AHI > 5/ h according to the AASM 2012 scoring rules and age more than 18 years were recruited from OPD and in-patients of SMS Medical College Jaipur. Patients on previous CPAP treatment, mixed or predominantly central sleep apnea, known diabetics and language barriers or cognitive or psychiatric disorders that made informed consent difficult to obtain were excluded. OBSERVATION: During the study period, 65 patients with treatment naïve OSA and a mean age of 52.28±10.92 year, a mean body mass index (BMI) of 34.73±7.20 kg/m2 underwent thyroid function tests. In the OSA patients, the prevalence of newly diagnosed clinical hypothyroidism was 12.3%. In Mild OSA the mean FT3 (ng/ml), FT4 (ng/dl), TSH (mIU/l) and mean AHI score was 3.10±0.71, 1.37±0.58, 3.64±1.37 and 7.74±3.55 respectively. Similarly, mean FT3 (ng/ml), FT4 (ng/dl), TSH (mIU/l) and mean AHI score were 2.97±0.93, 1.46±0.79, 6.33±8.05 and 17.42±88.90 respectively in moderate OSA and 3.32±0.58, 1.23±0.46, 3.55±1.82 and 45.54±21.38 respectively in severe OSA. There was a statistically significant difference between mild moderate and severe OSA regarding thyroid profile as well as BMI with p of <0.05. CONCLUSION: The prevalence of hypothyroidism was common among patients with OSA and the severity of OSA correlated with thyroid function tests and BMI.

Controlling Nucleation Pathways in Zeolite Crystallization: Seeding Conceptual Methodologies for Advanced Materials Design.

A core objective of synthesizing zeolites for widespread applications is to produce materials with properties and corresponding performances that exceed conventional counterparts. This places an impetus on elucidating and controlling processes of crystallization where one of the most critical design criteria is the ability to prepare zeolite crystals with ultrasmall dimensions to mitigate the deleterious effects of mass transport limitations. At the most fundamental level, this requires a comprehensive understanding of nucleation to address this ubiquitous materials gap. This Perspective highlights recent methodologies to alter zeolite nucleation by using seed-assisted protocols and the exploitation of interzeolite transformations to design advanced materials. Introduction of crystalline seeds in complex growth media used to synthesize zeolites can have wide-ranging effects on the physicochemical properties of the final product. Here we discuss the diverse pathways of zeolite nucleation, recent breakthroughs in seed-assisted syntheses of nanosized and hierarchical materials, and shortcomings for developing generalized guidelines to predict synthesis outcomes. We offer a critical analysis of state-of-the-art approaches to tailor zeolite crystallization wherein we conceptualize whether parallels between network theory and zeolite synthesis can be instrumental for translating key findings of individual discoveries across a broader set of zeolite crystal structures and/or synthesis conditions.

Management of patients after failed peroral endoscopic myotomy: a multicenter study.

BACKGROUND: Although peroral endoscopic myotomy (POEM) is highly effective for the management of achalasia, clinical failures may occur. The optimal management of patients who fail POEM is not well known. This study aimed to compare the outcomes of different management strategies in patients who had failed POEM. METHODS: This was an international multicenter retrospective study at 16 tertiary centers between January 2012 and November 2019. All patients who underwent POEM and experienced persistent or recurrent symptoms (Eckardt score > 3) were included. The primary outcome was to compare the rates of clinical success (Eckardt score ≤ 3) between different management strategies. RESULTS : 99 patients (50 men [50.5 %]; mean age 51.4 [standard deviation (SD) 16.2]) experienced clinical failure during the study period, with a mean (SD) Eckardt score of 5.4 (0.3). A total of 29 patients (32.2 %) were managed conservatively and 70 (71 %) underwent retreatment (repeat POEM 33 [33 %], pneumatic dilation 30 [30 %], and laparoscopic Heller myotomy (LHM) 7 [7.1 %]). During a median follow-up of 10 (interquartile range 3 - 20) months, clinical success was highest in patients who underwent repeat POEM (25 /33 [76 %]; mean [SD] Eckardt score 2.1 [2.1]), followed by pneumatic dilation (18/30 [60 %]; Eckardt score 2.8 [2.3]), and LHM (2/7 [29 %]; Eckardt score 4 [1.8]; P = 0.12). A total of 11 patients in the conservative group (37.9 %; mean Eckardt score 4 [1.8]) achieved clinical success. CONCLUSION : This study comprehensively assessed an international cohort of patients who underwent management of failed POEM. Repeat POEM and pneumatic dilation achieved acceptable clinical success, with excellent safety profiles.

Effect of an additional neurosurgical resident on procedure length, operating room time, estimated blood loss, and post-operative length-of-stay.

Introduction: Neurosurgical residency training is costly, with expenses largely borne by the academic institutions that train residents. One expense is increased operative duration, which leads to poorer patient outcomes. Although other studies have assessed the effect of one resident assisting, none have investigated two residents; thus, we sought to investigate if two residents versus one scrubbed-in impacted operative time, estimated blood loss (EBL), and length-of-stay (LOS).Methods: In this retrospective review of patients who underwent a neurosurgical procedure involving one or two residents between January 2013 and April 2016, we performed multivariable linear regression to determine if there was an association between resident participation and case length, operating room time, EBL, and LOS. We also included patient demographics, attending surgeon, day of the week, start time, pre-operative LOS, procedure performed, and other variables in our model. Only procedures performed at least 40 times during the study period were analyzed.Results: Of 860 procedures that met study criteria, 492 operations were one of six procedures performed at least 40 times, which were anterior cervical discectomy and fusion, cerebrospinal fluid (CSF) shunt insertion, CSF shunt revision, lumbar laminectomy, intracranial hematoma evacuation, and non-skull base, supratentorial parenchymal brain tumor resection. An additional resident was associated with a 35.1-min decrease (p = .01) in operative duration for lumbar laminectomies. However, for intracranial hematoma evacuations, an extra resident was associated with a 24.1 min increase (p = .03) in procedural length. There were no significant differences observed in the other four surgeries.Conclusion: An additional resident may lengthen duration of intracranial hematoma evacuations. However, two residents scrubbed-in were associated with decreased lumbar laminectomy duration. Overall, an extra resident does not increase procedural duration, total operating room utilization, EBL, or post-operative LOS. Allowing two residents to scrub in may be a safe and cost-effective method of educating neurosurgical residents.

LAG-3, TIM-3 and VISTA Expression on Tumor-Infiltrating Lymphocytes in Oropharyngeal Squamous Cell Carcinoma-Potential Biomarkers for Targeted Therapy Concepts.

Tumor growth and survival requires a particularly effective immunosuppressant tumor microenvironment (TME) to escape destruction by the immune system. While immunosuppressive checkpoint markers like programmed cell death 1 ligand (PD-L1) are already being targeted in clinical practice, lymphocyte-activation-protein 3 (LAG-3), T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) and V-domain Ig suppressor of T cell activation (VISTA) inhibitors are currently under investigation in clinical trials. Reliable findings on the expression status of those immune checkpoint inhibitors on tumor-infiltrating lymphocytes (TILs) in the TME of oropharyngeal squamous cell carcinoma (OPSCC) are lacking. This work aims to describe the expression of LAG-3, TIM-3, and VISTA expression in the TME of OPSCC. We created a tissue microarray of paraffin-embedded tumor tissue of 241 OPSCC. Expression of the immune checkpoint protein LAG-3, TIM-3, and VISTA in OPSCC was evaluated using immunohistochemistry and results were correlated with CD8+ T-cell inflammation and human papillomavirus (HPV)-status. 73 OPSCC stained positive for LAG-3 (31%; HPV+:44%; HPV-:26%, p = 0.006), 122 OPSCC stained positive for TIM-3 (51%; HPV+:70%; HPV-:44%, p < 0.001) and 168 OPSCC (70%; HPV+:75%; HPV-:68%, p = 0.313) for VISTA. CD8+ T-cells were significantly associated with LAG-3, TIM-3 and VISTA expression (p < 0.001, p < 0.001, p = 0.007). Immune checkpoint therapy targeting LAG-3, TIM-3, and/or VISTA could be a promising treatment strategy especially in HPV-related OPSCC. Future clinical trials investigating the efficacy of a checkpoint blockade in consideration of LAG-3, TIM-3, and VISTA expression are required.

Organic-Free Interzeolite Transformation in the Absence of Common Building Units.

Zeolite crystals can be used as seeds or aluminosilicate sources in syntheses to control polymorphs and/or reduce the quantity of organics used as structure-directing agents. A frequently invoked hypothesis for interzeolite transformations is that zeolites share some underlying similarity in structure, most notably in cases pertaining to organic-free syntheses. Herein, we show for the first time that ZSM-5 (MFI) can be directly obtained from USY (FAU) through an interzeolite transformation between parent-daughter structures lacking common building units in the absence of a structure-directing agent and seeds. We show that interzeolite transformation leads to a crystalline product with fewer defects. Our findings also reveal that ZSM-5 is a metastable intermediate that undergoes further transformation to mordenite (MOR) and quartz. The MFI-to-MOR transition is counter to reported trends for which transformations lead to structures with reduced molar volume. Herein, we propose mechanistic arguments that suggest the driving force for interzeolite transformation is more complex than guidelines posited in the literature.

Graphene's Partial Transparency to van der Waals and Electrostatic Interactions.

Graphene is the thinnest known two-dimensional (2D) material. This thinness is responsible for graphene's well-known optical transparency. In addition to being transparent to light, its extreme thinness and nonpolar nature also render graphene partially transparent to van der Waals and electrostatic interactions. This enables media present on opposite sides of a graphene sheet to sense or feel each other and be influenced by each other. Such crosstalk between materials separated by an impermeable barrier is impossible for typical barrier or coating materials that are usually thick enough to completely screen out such interactions. In this article, we review graphene's partial transparency to atomic interactions at the liquid-solid, solid-solid, and liquid-liquid interfaces. We compare graphene with other 2D materials such as hexagonal boron nitride and show that the extent of graphene's transparency is strongly dependent on the nature and interaction range of the materials placed on opposite sides of the graphene layer. We end with recommendations for future research to better understand the underlying science and to develop practical applications of this exciting phenomena.

Using Chemoattractants to Lure Bacteria to Contact-Killing Surfaces.

Antimicrobial surfaces with covalently attached biocidal functionalities only kill microbes that come into direct contact with the surfaces (contact-killing surfaces). Herein, the activity of contact-killing surfaces is shown to be enhanced by using gradients in the concentration of soluble chemoattractants (CAs) to attract bacteria to the surfaces. Two natural and nonbiocidal CAs (aspartate and glucose) were used to attract bacteria to model surfaces decorated with quaternary ammonium groups (known to kill bacteria that come into contact with them). These results demonstrate the killing of Escherichia coli and Salmonella typhimurium, two common pathogens, at levels 10- to 20-times greater than that of the native surfaces alone. This approach is general and provides new strategies for the design of active or dynamic contact-killing surfaces with enhanced antimicrobial activities.

A Ratiometric Sensor Using Single Chirality Near-Infrared Fluorescent Carbon Nanotubes: Application to In Vivo Monitoring.

Advances in the separation and functionalization of single walled carbon nanotubes (SWCNT) by their electronic type have enabled the development of ratiometric fluorescent SWCNT sensors for the first time. Herein, single chirality SWCNT are independently functionalized to recognize either nitric oxide (NO), hydrogen peroxide (H(2)O(2)), or no analyte (remaining invariant) to create optical sensor responses from the ratio of distinct emission peaks. This ratiometric approach provides a measure of analyte concentration, invariant to the absolute intensity emitted from the sensors and hence, more stable to external noise and detection geometry. Two distinct ratiometric sensors are demonstrated: one version for H(2)O(2), the other for NO, each using 7,6 emission, and each containing an invariant 6,5 emission wavelength. To functionalize these sensors from SWCNT isolated from the gel separation technique, a method for rapid and efficient coating exchange of single chirality sodium dodecyl sulfate-SWCNT is introduced. As a proof of concept, spatial and temporal patterns of the ratio sensor response to H(2)O(2) and, separately, NO, are monitored in leaves of living plants in real time. This ratiometric optical sensing platform can enable the detection of trace analytes in complex environments such as strongly scattering media and biological tissues.

Multimap formation in visual cortex.

An extrastriate visual area such as V2 or V4 contains neurons selective for a multitude of complex shapes, all sharing a common topographic organization. Simultaneously developing multiple interdigitated maps--hereafter a "multimap"--is challenging in that neurons must compete to generate a diversity of response types locally, while cooperating with their dispersed same-type neighbors to achieve uniform visual field coverage for their response type at all orientations, scales, etc. Previously proposed map development schemes have relied on smooth spatial interaction functions to establish both topography and columnar organization, but by locally homogenizing cells' response properties, local smoothing mechanisms effectively rule out multimap formation. We found in computer simulations that the key requirements for multimap development are that neurons are enabled for plasticity only within highly active regions of cortex designated "learning eligibility regions" (LERs), but within an LER, each cell's learning rate is determined only by its activity level with no dependence on location. We show that a hybrid developmental rule that combines spatial and activity-dependent learning criteria in this way successfully produces multimaps when the input stream contains multiple distinct feature types, or in the degenerate case of a single feature type, produces a V1-like map with "salt-and-pepper" structure. Our results support the hypothesis that cortical maps containing a fine mixture of different response types, whether in monkey extrastriate cortex, mouse V1 or elsewhere in the cortex, rather than signaling a breakdown of map formation mechanisms at the fine scale, are a product of a generic cortical developmental scheme designed to map cells with a diversity of response properties across a shared topographic space.