Visual Evidence Research Articles

Track My Phone : Integrated Image Capture and Location Tracking

The growing prevalence of mobile phone theft poses significant threats to personal security and data privacy, demanding innovative solutions beyond traditional security measures. This project introduces GeoCapture, an integrated system combining real-time location tracking with automated image capture to enhance the recovery of stolen or lost mobile devices. Leveraging GPS and Wi-Fi triangulation, the system provides precise location data, while the device’s front and rear cameras capture images during unauthorized access attempts, such as failed logins or SIM card changes. These images, along with location details, are securely transmitted to a cloud server and made accessible to users through an intuitive web or mobile interface. With its seamless combination of advanced tracking, visual evidence collection, and real-time notifications, GeoCapture empowers users to act swiftly, safeguard their data, and improve recovery outcomes, offering a robust solution to the challenges of mobile device theft in today’s digital age. Key Words: MobileSecurity, GeoCapture, LocationTracking, ImageCapture, DataProtection

The efficiency of isocyanate coating on the basalt fibre surface for the mechanical performance of elastomeric polyurethane composites

The influence of the isocyanate layer on fibre surface to mechanical, thermo-mechanical, processing, and morphological properties of basalt fibre (BF) reinforced elastomeric polyurethane (EPU) composites was examined by utilizing tensile test data and Shore hardness measurements, dynamic mechanical analysis (DMA), melt flow index (MFI) and scanning electron microscopy (SEM) techniques. BF was modified with an isocyanate functional group containing silane modifier. Isocyanate moieties on BF surface were confirmed via functional group analysis by infrared spectroscopy. SEM/EDX analysis was also used to visualize the sized and desized BF surfaces. Composite samples were fabricated using conventional processing methods, including extrusion and injection molding. Silane covering involving isocyanate functional group on fibre positively affected the tensile strength and tensile modulus of composites. Percent elongation of EPU showed a reduction trend with the incorporation of both sized and desized BF. The shore hardness of EPU increased by BF inclusions. According to DMA results, higher storage modulus values were obtained for surface-modified BF-filled composites compared to desized BF ones. BF additions resulted in no remarkable change in the MFI parameter of EPU. SEM images represented visual evidence for enhancement in mechanical performance by investigating better adhesion of the isocyanate layer of BF to EPU matrix concerning desized BF. The importance of surface sizing on BF surface in the case of BF-reinforced EPU composite applications was evaluated based on the compatibility of composite phases.

Pericoronary adipose tissue feature analysis in computed tomography calcium score images in comparison to coronary computed tomography angiography.

We investigated the feasibility and advantages of using non-contrast CT calcium score (CTCS) images to assess pericoronary adipose tissue (PCAT) and its association with major adverse cardiovascular events (MACE). PCAT features from coronary computed tomography angiography (CCTA) have been shown to be associated with cardiovascular risk but are potentially confounded by iodine. If PCAT in CTCS images can be similarly analyzed, it would avoid this issue and enable its inclusion in formal risk assessment from readily available, low-cost CTCS images. To identify coronaries in CTCS images that have subtle visual evidence of vessels, we registered CTCS with paired CCTA images having coronary labels. We developed an "axial-disk" method giving regions for analyzing PCAT features in three main coronary arteries. We analyzed hand-crafted and radiomic features using univariate and multivariate logistic regression prediction of MACE and compared results against those from CCTA. Registration accuracy was sufficient to enable the identification of PCAT regions in CTCS images. Motion or beam hardening artifacts were often prevalent in "high-contrast" CCTA but not CTCS. Mean HU and volume were increased in both CTCS and CCTA for the MACE group. There were significant positive correlations between some CTCS and CCTA features, suggesting that similar characteristics were obtained. Using hand-crafted/radiomics from CTCS and CCTA, AUCs were 0.83/0.79 and 0.83/0.77, respectively, whereas Agatston gave AUC = 0.73. Preliminarily, PCAT features can be assessed from three main coronary arteries in non-contrast CTCS images with performance characteristics that are at the very least comparable to CCTA.

Agnès Varda’s the ethics and the strategies of omission

Abstract This article and the video essay are about Agnès Varda’s love, forgiveness and standing one’s ground through at times a strategy of omission and absence. The article also aims to suggest that her filmmaking was conceptually rooted in Lacanian psychoanalysis whilst retaining its commitment to social justice and feminism at all times. In my own work, I have suggested that in order to subvert the patriarchy, it is at times necessary to be ‘nasty’ (Piotrowska Piotrowska, The nasty woman and the neo-femme fatale in contemporary cinema, Routledge, London, 2019; Piotrowska, Agnieszka. 2014, 2023. Psychoanalysis and Ethics in Documentary Film, London and New York: Routledge). This is not the case with the work and life of Agnès Varda, whose output I argue is characterised by boldness, rigour and care. This article is linked to the video essay which inspired the article and the thinking behind it. The video essay, the original version of which was presented at the plenary session of the Visible Evidence conference in 2019 at the University of Southern California, UD, has the style of a music video and focuses on love and loss.

Monitoring CO as a plant signaling molecule under heavy metal stress using carbon nanodots.

Carbon monoxide (CO) is widely recognized as a significant environmental pollutant and is associated with numerous instances of accidental poisoning in humans. However, it also serves a pivotal role as a signaling molecule in plants, exhibiting functions analogous to those of other gaseous signaling molecules, including nitric oxide (NO) and hydrogen sulfide (H2S). In plant physiology, CO is synthesized as an integral component of the defense mechanism against oxidative damage, particularly under abiotic stress conditions such as drought, salinity, and exposure to heavy metals. Current research methodologies have demonstrated a lack of effective tools for monitoring CO dynamics in plants during stress conditions, particularly in relation to heavy metal accumulation across various developmental stages. Therefore, development of a sensor capable of detecting CO in living plant tissues is essential, as it would enable a deeper understanding of its biological functions, underlying mechanisms, and metabolic pathways. In response to this gap, the present study introduces a novel technique for monitoring CO production and activity in plants using nitrogen-doped carbon quantum dots (N-CQDs). These nanodots exhibited exceptional biocompatibility, low toxicity, and environmentally sustainable characteristics, rendering them an optimal tool for CO detection via fluorescence quenching mechanism, with a detection limit (LOD) of 0.102 μM. This innovative nanomarker facilitated the detection of trace quantities of CO within plant cells, providing new insights into plant stress responses to heavy metals such as Cu, Zn, Pb, Ru, Cr, Cd, and Hg, as well as the processes involved in seed germination. Additionally, confocal microscopy validated the interaction between CO and N-CQDs, yielding visual evidence of CO binding within plant cells, further enhancing the understanding of CO's role in plant biology.

The Voice of Visual Evidence: Performance Theory, the MacGyver Factor, and Photojournalistic Authority

Historically, journalism’s claims to authority for photojournalistic work have largely rested on the camera’s technical perfection. Digital media, including AI, have disrupted this authority, as it is now possible to not just alter a photographic image but to construct one with merely a prompt. This essay argues that the crisis of photographic truth requires a paradigmatic shift and suggests that performance theory offers conceptual remedy. Performance theory, with its roots in anthropology and emphasis on embodiment, is offered as lens for studying photojournalism, shifting from the examination of texts to the photojournalists themselves. With its emphasis on human action, performance theory offers a new way of thinking about just what it is that photojournalists do and how their practice constructs visual evidence – pointing a way forward in the age of deep fakes.

Visual Location of Oxygen Vacancies on Bismuth Titanate Nanosheets with Periodic Quantum Well and Promoting H2O2 Photosynthesis.

Oxygen vacancy (OV) defect engineering plays a crucial role in enhancing photocatalytic efficiency. However, the direct visual characterization of oxygen vacancies still remains technically limited. Herein, a bismuth titanate (Bi4Ti3O12, BTO-OV) model photocatalyst containing oxygen vacancies is constructed through density functional theory (DFT) calculations to reveal the influence mechanism of distinctive periodic quantum well and oxygen vacancies on the charge transfer behavior in BTO. Notably, the distribution of oxygen vacancies is directly observed using the low-dose integrated differential phase contrast-scanning transmission electron microscopy (iDPC-STEM), providing visual evidence for the location of these oxygen vacancies in BTO-OV. Furthermore, the theoretical calculation results are verified by characterizing the photoelectric properties and conducting performance tests on the hydrogen peroxide (H2O2) photosynthesis. Specifically, the oxygen vacancies and distinctive periodic quantum well in BTO-OV accelerate charge separation, leading to a H2O2 photosynthesis efficiency reaching 5278 µm g-1 h-1, which is 5 times that of the original BTO. This work offers theoretical and experimental references for the visual characterization of oxygen vacancies and the improvement of the charge transfer mechanism.

Nano-viscosimetry analysis of membrane disrupting peptide magainin2 interactions with model membranes.

The rapid spread of antibiotic-resistant strains of bacteria has created an urgent need for new alternative antibiotic agents. Membrane disrupting antimicrobial peptides (AMPs): short amino acid sequences with bactericidal and fungicidal activity that kill pathogens by permeabilizing their plasma membrane may offer a solution for this global health crisis. Magainin 2 is an AMP secreted by the African clawed frog (Xenopus laevis) that is described as a toroidal pore former membrane disrupting AMP. Magainin 2 is one of the most thoroughly studied AMPs, yet its mechanism of action is still largely hypothetical: visual evidence of the pore formation is lacking, and the molecular mechanism leading to pore formation is still debated. In the present study, quartz crystal microbalance (QCM) based viscoelastic fingerprinting analysis supported by dye leakage experiments and atomic force microscopy (AFM) imaging was used to glean deeper insights into the mechanism of action. The effect of membrane charge, acyl chain unsaturation and cholesterol concentration were also investigated. The results show lipid specific disruptive mechanism of magainin 2. QCM nano-viscometry measurements revealed the presence of distinct stages in the mechanism of magainin 2 action that, with dye leakage data, confirm the existence of an initial transient pore stage that may result in peptide flip-flop between the outer and inner membrane leaflets. There is evidence of a further mechanistic stage at high peptide concentrations that is consistent with membrane collapse into a peptide-lipid mixed phase that is distinct from the transient pore formation. The results confirm some of the earliest hypotheses about magainin 2 action, while also highlighting the membrane modulating effect of this peptide.

Exploring the intricate studies on low-density polyethylene (LDPE) biodegradation by Bacillus cereus AP-01, isolated from the gut of Styrofoam-fed Tenebrio molitor larvae.

This study aims to investigate the biodegradation potential of a gut bacterial strain, Bacillus cereus AP-01, isolated from Tenebrio molitor larvae fed Styrofoam, focusing on its efficacy in degrading low-density polyethylene (LDPE). The biodegradation process was evaluated through a series of assays, including clear zone assays, biodegradation assays, and planktonic cell growth assessments in mineral salt medium (MSM) over a 28-day incubation period. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to characterize the alterations in LDPE pellets, followed by molecular characterization. Over three months, sterile soil + LDPE pellets were treated with different concentrations of gut bacterial strain. The degradation capabilities were assessed by measuring pH, total microbial counts, carbon dioxide evolution, weight loss, and conducting phase contrast microscopy and mechanical strength tests. Results demonstrated that MSM containing LDPE as a carbon source with gut bacterial strain produced a clear zone and enhanced planktonic cell growth. FTIR analysis revealed the formation of new functional groups in the LDPE, while SEM images displayed surface erosion and cracking, providing visual evidence of biodegradation. Molecular characterization confirmed the strain as Bacillus cereus AP-01 (NCBI Accession Number: OR288218.1). A 10% inoculum concentration of Bacillus cereus AP-01 exhibited increased soil bacterial counts, carbon dioxide evolution, and pH levels, alongside a notable weight loss of 30.3% in LDPE pellets. Mechanical strength assessments indicated substantial reductions in tensile strength (7.81 ± 0.84 MPa), compression (4.92 ± 0.53 MPa), hardness (51.96 ± 5.62 shore D), flexibility (10.62 ± 1.15 MPa), and impact resistance (14.79 ± 0.94 J). These findings underscore the biodegradation potential of Bacillus cereus AP-01, presenting a promising strategy for addressing the global LDPE pollution crisis.

Antimicrobial photodynamic inactivation of Pseudomonas aeruginosa persister cells and biofilms.

Pseudomonas aeruginosa is a hard-to-treat human pathogen for which new antimicrobial agents are urgently needed. P. aeruginosa is known for forming biofilms, a complex aggregate of bacteria embedded in a self-generated protective matrix that enhance its resistance to antibiotics and the immune system. Within the biofilm, persister cells, sub-populations of slow-growing or growth-arrested cells, are associated with recalcitrance of infections and antibiotic treatment failure. Here, we investigate the influence of the anionic photosensitiser chlorophyllin (CHL)1 exposed to red light alone and in combination with an activator of the mechanosensitive channels butylparaben (BP) on P. aeruginosa growing cells, persister cells, and biofilms. Antimicrobial susceptibility tests were performed using the broth microdilution checkerboard method. Serine hydroxamate (SHX) was used for the induction of persister cells. Under illumination, a combination of CHL (250 µg/ml) and BP (97.12 µg/ml) reduced the number of growing cells and persister cells by 2.2±0.46 log10 and 1.7±0.15 log10, respectively after 30 min of exposure at 79 J/cm2. A higher concentration of BP (194.23 µg/ml) or longer exposure time (60 min at 158 J/cm2) effectively eliminated approximately ≥99.99 % of growing and persister cells. Visual evidence from confocal and TEM images illustrates the influence of CHL and red light, which intensifies when combined with BP. Nevertheless, the addition of BP did not enhance the efficacy of CHL against biofilms; CHL (500 µg/ml) reduced biofilm viability by 2.6 log10 at 791 J/cm2. No toxicity has been observed in darkness. This study highlights the potential antimicrobial effect of CHL against P. aeruginosa.

Normative prospective data on automatically quantified retinal morphology correlated to retinal function in healthy ageing eyes by two microperimetry devices.

The relationship between retinal morphology, as assessed by optical coherence tomography (OCT), and retinal function in microperimetry (MP) has not been well studied, despite its increasing importance as an essential functional endpoint for clinical trials and emerging therapies in retinal diseases. Normative databases of healthy ageing eyes are largely missing from literature. Healthy subjects above 50 years were examined using two MP devices, MP-3 (NIDEK) and MAIA (iCare). An identical grid, encompassing 45 stimuli was used for retinal sensitivity (RS) assessment. Deep-learning-based algorithms performed automated segmentation of ellipsoid zone (EZ), outer nuclear layer (ONL), ganglion cell layer (GCL) and retinal nerve fibre layer (RNFL) from OCT volumes (Spectralis, Heidelberg). Pointwise co-registration between each MP stimulus and corresponding location on OCT was performed via registration algorithm. Effect of age, eccentricity and layer thickness on RS was assessed by mixed effect models. Three thousand six hundred stimuli from twenty eyes of twenty patients were included. Mean patient age was 68.9 ± 10.9 years. Mean RS for the first exam was 28.65 ± 2.49 dB and 25.5 ± 2.81 dB for MP-3 and MAIA, respectively. Increased EZ thickness, ONL thickness and GCL thickness were significantly correlated with increased RS (all p < 0.001). Univariate models showed lower RS with advanced age and higher eccentricity (both p < 0.05). This work provides reference values for healthy age-related EZ and ONL-thicknesses without impairment of visual function and evidence for RS decrease with eccentricity and increasing age. This information is crucial for interpretation of future clinical trials in disease.

The Child in the Adult: Narrative and Nachträglichkeit in Henry James and Freud

At the intersection of literature and psychoanalysis, this essay draws on Freud’s discovery of the infantile sexual unconscious to explore moments in the late novels of Henry James, in which an adult protagonist both recognizes and disavows the visible evidence of a sexual relationship. The essay considers Hans Holbein’s 1533 painting, The Ambassadors, as a possible source for Henry James’ choice of title for his 1903 novel: the painting’s visual play with point of view touches on the narrative disavowal of what is there to be seen. The essay explores some narrative dimensions of Freud’s writing to highlight the dynamic disclosure of the infantile within the adult. The concept of Nachträglichkeit, recognizing the deferred or belated impact of disruptive recurrences in mental life, helps to understand such moments and gives insight, more broadly, into narrative experience. Drawing on Nachträglichkeit as a principle of mental life, the essay explores the resonances of infantile sexuality, fantasy, and trauma in narrative, and more generally, as a resource in creative expression.

Superresolution Imaging Reveals the Spatial Organization of CD81 Microdomains in Regulating Membrane Signaling on Jurkat T Cell Microvilli.

Tetraspanin proteins are closely associated with high-curvature membrane structures and play key roles in organizing membrane domains and regulating membrane signaling in immune cells. However, their specific roles in regulating T cell membrane signaling, particularly within the microvilli often characteristic of these cells, remain poorly understood. Here, we used Jurkat T cells as a model system and investigated CD81 as a membrane of the tetraspanin family. Using total internal reflection fluorescence (TIRF) microscopy and structured illumination microscopy (SIM), we identified an enrichment of the tetraspanin CD81 microdomains along the actin-rich membrane microvilli. At the tip of the microvilli, SIM images revealed the spatial colocalization of CD81 with T cell receptors (TCR) and CD63, implying a potential role for CD81 in regulating TCR signaling in conjunction with CD63. Spatial analysis of CD81 and CD63 microdomains from the dual-color SIM data revealed their preference for associating with each other. Cluster analysis of direct stochastic optical reconstruction microscopy (dSTORM) data revealed that in vitro T cell activation results in reduced domain sizes and increased domain separation of CD81. These findings provide visual evidence of the spatial organization and rearrangement of CD81 on the T cell microvilli, highlighting its potential role in signal regulation on specialized membrane protrusions.

Rome – The Unauthorized Version

This article looks at the interaction of the people of Rome with their past and the creation of sites of memory with a particular focus on the period from the Risorgimento and onwards. It uses visual, textual and oral evidence to examine how the monuments of the ancient past were used as places to live and work. Being an integral part of the daily lives of the citizens meant that these monuments became important symbols of their identity and social cohesion. The use of ancient Rome for political purposes by the Risorgimento and Fascist governments was a separate heritage discourse, distinct from the daily interactions of ordinary peoplle. Using the memorial at the Fosse Ardeatine as a case-study explores how lieux de mémoire change status as succeeding generations reinterpret events and how monuments become co-opted into an Authorised Heritage Discourse.

The Blindfold Test: Helping to decide whether an effect reflects visual processing or higher-level judgment.

Experimenters often ask subjects to rate displays in terms of high-level visual properties, such as animacy. When do such studies measure subjects' visual impressions, and when do they merely reflect their judgments that certain features should indicate animacy? Here we introduce the 'Blindfold Test' for helping to evaluate the evidence for whether an effect reflects perception or judgment. If the same effect can be obtained not only with visual displays but also by simply describing those displays, then subjects' responses may reflect higher-level reasoning rather than visual processing-and so other evidence is needed in order to support a 'perceptual' interpretation. We applied the Blindfold Test to three past studies in which observers made subjective reports about what they were seeing. In the first two examples, subjects rated stimuli in terms of high-level properties: animacy and physical forces. In both cases, the key findings replicated even when the visual stimuli were replaced with (mere) descriptions, and we conclude that these studies cannot by themselves license conclusions about perception. In contrast, a third example (involving motion-induced blindness) passed the test: subjects produced very different responses when given descriptions of the displays, compared to the visual stimuli themselves-providing compelling evidence that the original responses did not merely reflect such higher-level reasoning. The Blindfold Test may thus help to constrain interpretations of the mental processes underlying certain experimental results-especially for studies of properties that can be apprehended by both seeing and thinking.

A Hollowed-Out Heterometallic Cluster for Catalytic Knoevenagel Condensation.

Lanthanide-containing clusters are synthetically challenging and with significant chemical and materials applications. Herein, two isostructural heterometallic clusters of the formula (NO3)12@[Ln132Ni78(OH)292(IDA)48(CH3COO)96(NO3)12(H2O)78]Cl44⋅xH2O⋅yCH3OH (IDA=iminodiacetate; Ln=Gd 1, x=110, y=0; Ln=Eu 2, x=95, y=40) were obtained via co-hydrolysis of Ln3+ (Gd3+ or Eu3+) and Ni2+ in the presence of iminodiacetate (IDA). Crystallographic studies show that each features a truncated tetrahedral core of Ln132Ni78 within which a void of 1.1 nm in diameter; connecting the central cage and its exterior are four trumpet-like passageways surface-decorated with dinuclear units of [Gd(μ3-OH)2Gd]. Mass spectroscopic analyses indicate that both clusters maintained their structural integrity in aqueous solution, with cryo-electron microscopy providing the most convincing visual evidence in support of the cluster's solution stability. Size-selective Knoevenagel condensation, believed to occur in the passageways on the basis of experimental and molecular modeling results, was achieved in the presence of 1. The application of 1 as a uniquely structured molecular reactor and a recyclable heterogeneous catalyst was further illustrated by the one-pot three-component synthesis of biologically and pharmaceutically significant 4H-pyran derivatives.

A Hollowed‐Out Heterometallic Cluster for Catalytic Knoevenagel Condensation

AbstractLanthanide‐containing clusters are synthetically challenging and with significant chemical and materials applications. Herein, two isostructural heterometallic clusters of the formula (NO3)12@[Ln132Ni78(OH)292(IDA)48(CH3COO)96(NO3)12(H2O)78]Cl44⋅xH2O⋅yCH3OH (IDA=iminodiacetate; Ln=Gd 1, x=110, y=0; Ln=Eu 2, x=95, y=40) were obtained via co‐hydrolysis of Ln3+ (Gd3+ or Eu3+) and Ni2+ in the presence of iminodiacetate (IDA). Crystallographic studies show that each features a truncated tetrahedral core of Ln132Ni78 within which a void of 1.1 nm in diameter; connecting the central cage and its exterior are four trumpet‐like passageways surface‐decorated with dinuclear units of [Gd(μ3‐OH)2Gd]. Mass spectroscopic analyses indicate that both clusters maintained their structural integrity in aqueous solution, with cryo‐electron microscopy providing the most convincing visual evidence in support of the cluster‘s solution stability. Size‐selective Knoevenagel condensation, believed to occur in the passageways on the basis of experimental and molecular modeling results, was achieved in the presence of 1. The application of 1 as a uniquely structured molecular reactor and a recyclable heterogeneous catalyst was further illustrated by the one‐pot three‐component synthesis of biologically and pharmaceutically significant 4H‐pyran derivatives.

‘Richt honorabill’ ladies: Noble Power and Aristocratic Women in Sixteenth-Century Scotland

This essay began as a talk given in October 2023 to inaugurate an annual public lecture in honour of Jenny Wormald. It takes its inspiration from her work on noble power, re-examining how noblewomen in sixteenth-century Scotland employed that power. Visual and cultural evidence has been prioritised in the essay which is organised around two settings: the royal court and noble country seats. As the Stirling Heads show, noblewomen formed part of the public face of the Scottish court. They also exploited their right of access to the monarch to further their own and family interests. The arrival of renaissance country houses expanded noblewomen's central duty of running their residences, sometimes including managing the family estates. ‘Holding hous’ required the provision of hospitality and of the new country-house culture. Noblewomen formed a vital communication system linking the regions to the capital and court. Their informal networks helped negotiate the inter-relationships of birth and marital kindreds, of friendships and alliances. The female contribution to the success of noble families suggests a broader definition of Scottish noble power is required. Further exploration might also place that experience within the European context of the development of aristocratic elites.

Development of Polyurethane Elastomer-Based Bio-Composites Reinforced with Basaltic Pumice

Basaltic pumice has a black or gray appearance due to its iron and magnesium-rich komatiitic tuff composition. Pumice's porous structure allows the production of various polymer-based bio-composite materials for biomedical applications. This study developed bio-composite samples by incorporating basaltic pumice powder at 2.5, 5.0, 7.5, and 10.0 percent concentrations into an elastomeric polyurethane (EPU) matrix. The surface and elemental structure of basaltic pumice particles were investigated using the SEM/energy diffraction X-ray technique. The physical, mechanical, thermal, melt-flow, and morphological properties of bio-composites were studied experimentally. Findings showed a rise in Shore hardness and tensile modulus parameters and declined tensile elongation. According to the thermal study, introducing basaltic pumice resulted in a modest drop in the thermal stability of the EPU and an improvement in stability against mechanical deformations. Pumice loadings raised the melt flow and extrusion torque values of the EPU. The observation of the homogeneously distributed pumice particles in the EPU matrix is used as visual evidence to investigate the highest performance among the composites in the EPU sample with the lowest loading rate of 7.5% pumice. Overall, BP is effective as a reinforcing agent in EPU-based bio-composites at low additive percentages.

Cross-Modal Hashing Method With Properties of Hamming Space: A New Perspective.

Cross-modal hashing (CMH) has attracted considerable attention in recent years. Almost all existing CMH methods primarily focus on reducing the modality gap and semantic gap, i.e., aligning multi-modal features and their semantics in Hamming space, without taking into account the space gap, i.e., difference between the real number space and the Hamming space. In fact, the space gap can affect the performance of CMH methods. In this paper, we analyze and demonstrate how the space gap affects the existing CMH methods, which therefore raises two problems: solution space compression and loss function oscillation. These two problems eventually cause the retrieval performance deteriorating. Based on these findings, we propose a novel algorithm, namely Semantic Channel Hashing (SCH). First, we classify sample pairs into fully semantic-similar, partially semantic-similar, and semantic-negative ones based on their similarity and impose different constraints on them, respectively, to ensure that the entire Hamming space is utilized. Then, we introduce a semantic channel to alleviate the issue of loss function oscillation. Experimental results on three public datasets demonstrate that SCH outperforms the state-of-the-art methods. Furthermore, experimental validations are provided to substantiate the conjectures regarding solution space compression and loss function oscillation, offering visual evidence of their impact on the CMH methods.